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  • A number of new studies on ovarian cancer show “promising” results for patients who develop chemo-resistance
  • A Dutch study uses conventional chemotherapeutics more intensively
  • Another study uses a new class of drug discovered by the UK’s Institute of Cancer Research
  • Genetic testing is playing an increasing role in the reduction of chemo-resistance
  • Since 2014 the Royal Marsden NHS Trust Hospital in London has employed genetic profiling of ovarian cancer patients
  • The UK’s Chief Medical Officer suggests that whole genome sequencing should become standard practice on the NHS across cancer care
  • A new class of chemotherapeutic agent is directed at targeting cancers with defective DNA-damage repair
  • Improvements in cancer care have been both scientific and organizational
  • Utilizing and sequencing the treatment options for ovarian cancer may have a significant impact on the overall survival rates of patients
  • Multidisciplinary teams are transforming ovarian cancer care 
 
Improving ovarian cancer treatment 

Part II

Part-1 described ovarian cancer, the difficulties of diagnosing the disease early, and the challenges of developing effective screening mechanisms for it in pre-symptomatic women. Here, in part-2, we report new studies, which hold out the prospect of improved treatment options for women living with ovarian cancer. Both Commentaries draw on some of the world’s most eminent ovarian cancer clinicians and scientists.
 
1

Established chemotherapy agents combined and used intensively

The first study we describe is Dutch, published in 2017 in the British Journal of Cancer. It reports findings of a pioneering type of intensive chemotherapy, which was effective in 80% of patients with advanced ovarian cancer and whose first line of chemotherapy had failed. Currently, such patients have few options because more than 50% do not respond to follow-up chemotherapy.
 
Intensive combinations
The study, led by Dr. Ronald de Wit, of the Rotterdam Cancer Institute, involved 98 patients who first responded to chemotherapy only later to relapse. Patients in the study were divided into three groups according to the severity of their condition, and treated with a combination of two well established chemotherapy agents:  cisplatin and etopside, but the new treatment used the drugs much more intensively than usual.
 
Usually, chemotherapy is delivered as a course of a number of 21-day sessions (cycles) over several months. Between cycles patients are given time to recover from the toxic side effects, including neurotoxicity, nephrotoxicity, ototoxicity, and chemotherapy-induced nausea and vomiting (CINV). In de Wit’s study the combined chemotherapy drugs were given intensively, on a weekly basis, along with drugs to prevent adverse side effects.
 
Findings
Among the group of women in de Wit’s study who were most seriously ill, 46% responded to the new treatment, compared with less than 15% for current therapies. The response rates of the two groups of women who were least ill to the new treatment were 92% and 91%. This compares to responses of 50% and 20 to 30% with standard therapies. Overall, 80% of the women's tumours shrank, and 43% showed a complete response, with all signs of their cancers disappearing.
 
Immediate benefit
"We were delighted by the success of the study. The new drug combination was highly effective at keeping women alive for longer, giving real hope to those who would otherwise have had very little . . . . We were worried the women would be too ill to cope with the treatment, but in fact, they suffered relatively few side effects. And since these drugs are readily available, there's no reason why women shouldn't start to benefit from them right away," says de Wit.
 
2
 
ONX-0801 study

The second study we report was presented at the 2017 American Society of Clinical Oncology (ASCO) meeting in Chicago. It describes findings of an experimental new treatment that was found to dramatically shrink advanced ovarian cancer tumors, which researchers suggest is, “much more than anything that has been achieved in the last 10 years”.
 
“Very promising” findings
Dr. Udai Banerji, the leader of the study, is the Deputy Director of Drug Development at the UK’s Institute of Cancer Research (ICR). Banerji and his team were testing a drug, known as ONX-0801, for safety, but found that tumors, in half of the 15 women studied, shrank during the trial. A response Banerji called, “highly unusual”, and “very promising”. The drug, which is, “a completely new mechanism of action,” could add, “upward of six months to the lives of patients with minimal side effects”. If further clinical studies prove the drug’s effectiveness, it could potentially be used in early-stage ovarian cancer where, “the impact on survival may be better,” says Banerji.
 
New class of drug
ONX-0801 is the first in a new class of drug discovered by the ICR, and tested with the Royal Marsden NHS Foundation Trust. It attacks ovarian cancer by mimicking folic acid in order to enter the cancer cells. The drug then kills these cells by blocking a molecule called thymidylate synthase. ONX-0801 could be effective in treating the large group of chemo-resistant sufferers for whom there are currently limited options. Additionally, because the new therapy targets cancer cells and does not affect surrounding healthy cells, there are fewer side effects. Further, experts have developed tests to detect the cells that respond positively to this new treatment, which means oncologists can identify those women who are likely to benefit from the therapy the most.
 
Cautious note
Although the study is said to be “very promising”, Michel Coleman, Professor of Epidemiology at the London School of Hygiene & Tropical Medicine, suggests caution in interpreting its findings as it is such a small study and while, “shrinkage of tumors is important . . . it is not the same as producing the hoped-for extension of survival for women with ovarian cancer.”
 
3
 
Genetic testing

Resistance to chemotherapy can be reduced by DNA testing to obtain an increased knowledge of the molecular mechanisms of ovarian cancer pathogenesis, which facilitate personalized therapies that target certain subtypes of the disease. “Some people choose to have DNA testing because either they have developed cancer or family members have,” says David Bowtell, Professor and Head of the Cancer Genomics and Genetics Program at Peter MacCallum Cancer Centre, Melbourne, Australia. “In the context of cancer, personalized medicine is the concept that we look into the cancer cell and understand for that person what specific genetic changes have occurred in their cancer. Based on those specific changes, for that person we then decide on a type of therapy, which is most appropriate for the genetic changes that have occurred in that cancer . . . . . Typically this involves taking a sample of the cancer, running it through DNA sequencing machines, and using bioinformatics to interpret the information. Then, the results, which include gene mutations need to be interpreted by a multidisciplinary team, in order to decide the best possible treatment options for that particular patient,” says Bowtell: see videos below.
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How do genetic mutations translate into personalised medicine?


How is personalised medicine implemented?
 
Mainstreaming cancer genetics
Since 2014 the Royal Marsden NHS Trust Hospital in London has employed genetic profiling of ovarian cancer patients, and have used laboratories with enhanced genetic testing capabilities to streamline and speed up processing time, lower costs, and help meet the large and growing demand for rapid, accurate and affordable genetic testing. The program called, Mainstreaming Cancer Genetics, helps women cancer patients make critical decisions about their treatment options. Currently, fewer than 33% of patients are tested, but this study spearheaded the beginning of a significant change. In her 2017 Annual Report, Professor Dame Sally Davies, England’s Chief Medical Office suggested that within the next 5 years all cancer patients should be routinely offered DNA tests on the NHS to help them select the best personalized treatments.
 

Bringing genetic testing to patients
According to Nazneen Rahman, Professor and Head of the Division of Genetics and Epidemiology at the ICR, and Head of the Cancer Genetics Unit at the Royal Marsden Hospital, London, “There were two main problems with the traditional system for gene testing. Firstly, gene testing was slow and expensive, and secondly the process for accessing gene testing was slow and complex . . . . We used new DNA sequencing technology to make a fast, accurate, affordable cancer gene test, which is now used across the UK. We then simplified test eligibility and brought testing to patients in the cancer clinic, rather than making them have another appointment, often in another hospital.” 
 

More people benefiting from affordable rapid advanced genetic testing
Treatment strategies that improve the selectivity of current chemotherapy have the potential to make a dramatic impact on ovarian cancer patient outcomes. The Marsden is now offering genetic tests to three times more cancer patients a year than before the program started. The new pathway is faster, with results arriving within 4 weeks, as opposed to the previous 20-week waiting period. According to Rahman, “Many other centres across the country and internationally are adopting our mainstream gene testing approach. This will help many women with cancer and will prevent cancers in their relatives.” If the UK government acts on the recommendations of Davies, there could be a national center for genetic testing within the next 5 years.
 
4

PARP Inhibitors and personalized therapy
 
Since 2 seminal 2005 publications in Nature,  (Bryant et al, 2005; and Farmer et al, 2005) which reported the extremely high sensitivity of BRCA mutant cell lines to the enzyme poly (ADP-ribose) polymerase (PARP) inhibition, there has been a scientific race to exploit a new class of cancer drug called PARP inhibitors. The family of PARP inhibitors represents a widely researched and promising alternative for the targeted therapy of ovarian malignancies. Over the past few years, PARP inhibitors have successfully moved into clinical practice, and are now used to help improve progression-free survival in women with recurrent platinum-sensitive ovarian cancer.

 
Recent (PARP) approvals
In 2014, olaparib was the first PARP inhibitor to obtain EU approval as a treatment for ovarian cancer patients who had become resistant to platinum-based chemotherapy. In 2017, the FDA granted the drug ‘priority review’ as a maintenance therapy in relapsed patients with platinum-sensitive ovarian cancer while confirmatory studies are completed. In December 2016, the FDA granted ‘accelerated approval’ for rucaparib, another (PARP) inhibitor for the treatment of women with advanced ovarian cancers who have been treated with two or more chemotherapies, and whose tumors have specific BRCA gene mutations. 
 
Early in 2017, the drug niraparib was the first PARP inhibitor to be approved by the FDA for the maintenance treatment of adult patients with recurrent gynaecological cancers who are resistant to platinum-based chemotherapy.  The approval was based upon data from an international randomized, prospectively designed phase III clinical study, which enrolled 553 patients, and showed a clinically meaningful increase in progression-free survival (PFS) in women with recurrent ovarian cancer, regardless of BRCA mutation or biomarker status. In conjunction with the accelerated 2017 FDA approval for rucaparib, the FDA also approved a BRCA diagnostic test, which identifies patients with advanced ovarian cancer eligible for treatment with rucaparib.
 

New class of chemotherapies
PARP inhibitors may represent a potentially significant new class of chemotherapeutic agents directed at targeting cancers with defective DNA-damage repair. Currently, these drugs have a palliative indication for a relatively small cohort of patients. In order to widen the prospective patient population that would benefit from PARP inhibitors, predictive biomarkers based on a clearer understanding of the mechanism of action, and a better understanding of their toxicity profile will be required. Once this is achieved PARP inhibitors could to be employed in the curative, rather than the palliative setting.
 
5
 
The future of cancer care and multidisciplinary teams
 
According to Hani Gabra, Professor of Medical Oncology at Imperial College, London; and Head of AstraZeneca’s Oncology Discovery Unit, we now have “many options” for treating ovarian cancer. However, “how we utilize and sequence these options may have a significant impact on the overall survival of a patient. Better understanding of the disease through science is constantly turning up new options. For the first time in the last 5 years we are developing options in real time for patients. Patients almost are able to benefit from these options as they are relapsing from their disease. Keeping patients alive for longer allows them to access new treatments . . . It’s truly remarkable to see this in real time as a doctor,” says Gabra: see video.
 

A significant number of mostly private patients diagnosed with ovarian cancer draw comfort from the belief that they, “have the best oncologist”.  This view fails to grasp the challenges facing individual clinicians acting on their own to treat a devilishly complex disease such as ovarian cancer. “The main improvements in cancer care have been organizational and scientific.” says Gabra. “It is not enough to create new science and new treatments. It is also important to rigorously implement these. The most effective way to do this is via a ‘tumor board’ or a ‘multidisciplinary clinic or team’, where various specialists such as surgeons, radiotherapists, medical oncologists, pathologists, clinical nurse specialists, etc come together and discuss each individual patient. Such multidisciplinary discussion results in the best utilizations of currently available treatment options in the right sequence. It’s difficult to do this for a doctor acting on his or her own and making isolated decisions . . . Multidisciplinary decision-making has transformed cancer care,” says Gabra: see video.
 
 
Takeaways

This Commentary provides a flavor of some of the recent advances in ovarian cancer research and care, and suggests that treatment options have improved in the 4 years since Maurice Saatchi described ovarian cancer care as, “degrading, medieval and ineffective” leading “only to death”. However, it is worth stressing that care is both organizational and scientific, and multidisciplinary teams can transform care and prolong life.
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  • Ovarian cancer is a deadly disease that is challenging to diagnose and manage
  • Although it only accounts for 3% of cancers in women, it is the 5th leading cause of cancer death among women
  • If diagnosed and treated early before it spreads the 5-year survival rate is 92%
  • But only 15% of women with ovarian cancer are diagnosed early
  • The disease is hard to diagnose because it is rare, the symptoms are relatively benign, and there is no effective screening
  • Ovarian cancer is not one disease, but a collection of subtypes each demanding specific treatment pathways
  • Gold standard treatment is surgery followed by chemotherapy
  • A large proportion of patients develop resistance to chemotherapy
 
Improving ovarian cancer treatment

Part I
 
Are things beginning to improve for people living with ovarian cancer? When the British advertising magnate Lord Maurice Saatchi’s wife died of ovarian cancer in 2012 he described her treatment as, “degrading, medieval and ineffective” leading “only to death”. Ovarian cancer patients have long had limited treatment options, which have not changed much in the past two decades, but recently things have begun to change.

 
In this Commentary
 
This is the first of a 2-part Commentary on ovarian cancer, which briefly describes the condition, explains the difficulties of diagnosing it early, and discusses some of the challenges of developing effective screening mechanisms for the cancer in pre-symptomatic women. Part 2, which will follow separately next week, reports new studies, which hold out the prospect of improved treatment options for women living with ovarian cancer. It also suggests that improvements in ovarian cancer care are both organizational and scientific. Experts believe that they now have a number of treatment options available to them. Utilising and sequencing these appropriately can have a significant impact on the overall survival rates of patients. Multidisciplinary teams, which are not universally available to all ovarian cancer patients, bring together all specialisms involved in the therapeutic pathway to consider and suggest optimal treatment steps for individual patients, and make a significant contribution to improved ovarian cancer care. Both Commentaries draw on some of the world’s most eminent ovarian cancer clinicians and scientists.
 
Ovarian cancer: a complex and deadly disease
 
The ovaries are a pair of small organs located low in the stomach that are connected to the womb and store a woman’s supply of eggs. Ovarian cancer is driven by multicellular pathways, and is better understood as a collection of subtypes with changing origins and clinical behaviors, rather than as a single disease. The tumors often have heterogeneous cell populations, which form unique microcellular environments. The prevalence of ovarian cancer among gynecological malignancies is rising, and is one the most deadly and hard to treat malignancies. While the disease only accounts for about 3% of cancers in women, it is one of the most common types of cancer in women, the 5th leading cause of cancer-related death among women, and the deadliest of gynecologic cancers. The risk of ovarian cancer increases with age. It is rare in women younger than 40, most ovarian cancers develop after menopause. 50% of all ovarian cancers are found in women 63 or older. According to the American Cancer Society the five-year survival rate for all ovarian cancers is 45%. Most women are diagnosed with late-stage ovarian disease and, the 5-year survival rates for these patients are roughly 30%. Age adjusted survival rates of ovarian cancer are improving in most developed countries. For instance, between 1970 and 2010, the 10-year survival rates for ovarian cancer in England increased by 16%, and the 5-year survival rates have almost doubled. This is because of the favorable trends in the use of oral contraceptives, which were introduced early in developed countries. Declines in menopausal hormone use may also have had a favorable effect in older women as well as improved diagnosis, management and therapies. According to Public Health England, over the past 20 years the incidence of ovarian cancer in England has remained fairly stable, although it has decreased slightly in the last few years. Between 2008 and 2010 in England, 36% of some 14,000 women diagnosed with ovarian cancer died in the first year, and more than 1,600 died in the first month. There were 7,378 new cases of ovarian cancer in the UK in 2014 and more than 4,000 women died from the disease.
 
Benign symptoms difficult to diagnose

If ovarian cancer is diagnosed and treated early before it spreads from the ovaries to the abdomen, the 5-year relative survival rate is 92%. However, only 15% of all ovarian cancers are found at this early stage.  This is because it is hard to diagnose since the disease is so rare, the symptoms are relatively benign, and there is no effective screening. As a result, the illness tends not to be detected until the latter stages in around 60% of women, when the prognosis is poor. In about 20% of cases the disease is not diagnosed until it is incurable. Feeling bloated most days for three weeks or more is a significant sign of ovarian cancer. Other symptoms include: feeling full quickly, loss of appetite, pelvic or stomach pain, needing to urinate more frequently than normal, changes in bowel habit, feeling very tired, and unexplained weight loss.
 
“Tumors go from the earliest stage 1 directly to stage 3”
In the video below Hani Gabra, Professor of Medical Oncology at Imperial College, London; and Head of AstraZeneca’s Oncology Discovery Unit says, “Ovarian cancer is often diagnosed late because in many cases the disease disseminates into the peritoneal cavity almost simultaneously with the primary declaring itself. Unlike other cancers, the notion that ovarian cancer progresses from stage 1 to stage 2, to stage 3 is possibly mythological. The reality is, these cancer cells often commence in the fallopian tube with a very small primary tumor, which disseminates directly into the peritoneal cavity. In other words, the tumors go from the earliest of stage 1 directly to stage 3."
 
 
Ovarian cancer screening and CA-125

For years scientists have been searching for an effective screening test for ovarian cancer in pre-symptomtic women. The 2 most common are transvaginal ultrasound (TVUS) and the CA-125 blood test. The former uses sound waves to examine the uterus, fallopian tubes, and ovaries by putting an ultrasound wand into the vagina. It can help find a tumor in the ovary, but cannot tell if the tumor is cancerous or benign. Most tumors identified by TVUS are not cancerous. So far, the most promising screening method is CA-125, which measures a protein antigen produced by the tumor.
 
CA-125 studies
To-date, 2 large ovarian cancer screening studies have been completed: one in the US, and another in the UK. Both looked at using the CA-125 blood test along with TVUS to detect ovarian cancer. In these studies, more cancers were found in the women who were screened, and some were at an early stage. But the outcomes of the women who were screened were no better than the women who were not screened: the screened women did not live longer and were not less likely to die from ovarian cancer.

Another study published in 2017 in the Journal of Clinical Oncology screened 4,346 women over 3 years at 42 centers across the UK, undertook follow-up studies 5 years later, and came to similar conclusions as the 2 previous studies. Further, “there are a number of non-ovarian diseases, which can cause elevated CA-125’s. Breast cancer, endometriosis, and irritation of the peritoneal cavity can all cause elevated CA-125,” says Michael Birrer, Director of Medical Gynecologic Oncology at the Massachusetts General Hospital and Professor of Medicine at Harvard University.


Controversial findings
Findings from screening tests using CA-125 can give false positives for ovarian cancer, and this puts pressure on patients to have further, often unnecessary interventions, which sometimes include surgery. Also, the limitations of the CA-125 test mean that many women with early stage ovarian cancer will receive a false negative from testing, and not get further treatment for their condition. Thus, the potential role of CA-125 for the early detection of ovarian cancer is controversial, and therefore it has not been adopted for widespread screening in asymptomatic women.
 
In the video below Birrer explains that, “pre-operatively and during therapy physicians will usually check CA-125 as a measure of the effectiveness of the therapy. At the completion of therapy one would anticipate that the CA-125 would be normal. After that, it is somewhat controversial as to whether follow-up with CA-125 to test for recurring disease is clinically relevant,” says Birrer. Since the discovery of CA-125 in 1981, there has been intense research focus on novel biomarkers for cancer, and significant scientific advances in genomics, proteomic, and epigenomics etc., which have been extensively used in scientific discovery, but as yet no new major cancer biomarkers have been introduced to practicing oncologists. 

 
Limited treatment options

As most ovarian cancer patients are diagnosed late when the disease has already spread, treatment options are limited. The first line treatment is surgery called debulking, (also known as cytoreduction or cytoreductive surgery), which is the reduction of as much of the volume (bulk) of a tumor as possible. 
 
Be prepared for extensive surgery
Whether a patient is a candidate for surgery depends on a number of factors including the type, size, location, grade and stage of the tumor, pre-existing medical conditions, and in the case of a recurrence, when the last cancer treatment was performed, as well as general health factors such as age, physical fitness and other medical comorbidities. People diagnosed with ovarian cancer, “need to be prepared to have extensive surgery because the real extent of the tumor dissemination cannot be detected by conventional imagining pre-operatively,” says Professor Christina Fotopoulou, consultant gynaecological oncologist at Queen Charlotte's & Chelsea Hospital, London: see video below. 
 
 
Platinum resistance

Surgery is usually followed by chemotherapy. There are more than 100 chemotherapy agents used to treat cancer either alone or in combination. Chemotherapy drugs target cells at different phases of the process of forming new cells, called the cell cycle. Understanding how these drugs work helps oncologists predict, which drugs are likely to work well together. Clinicians can also plan how often doses of each drug should be given based on the timing of the cell phases. Chemotherapy drugs can be grouped by their chemical composition, their relationship with other drugs, their utility in treating specific forms of cancer, and their side effects.  
 
You can reduce chemotherapy resistance by using a combination of drugs that target different processes in the cancer so that the probability that the cancer will simultaneously become resistant to both drugs is much lower than if you use one drug at a time, ” says David Bowtell,  Professor and Head of the Cancer Genomics and Genetics Program at Peter MacCallum Cancer Centre, Melbourne, Australia: see video:
 
 
Improving the chemotherapy agent cisplatin
The standard chemotherapy treatment for ovarian cancer is a combination of a platinum compound, such as cisplatin or carboplatin, and a taxane, which represents a class of drug originally identified from plants. Since cisplatin’s discovery in 1965 and its FDA approval in 1978, it has been used continuously in treatments for several types of cancer, and is best known as a cure for testicular cancer. Scientists have searched for ways to improve the anti-tumor efficacy of platinum based drugs, reducing their toxicity, strengthening them against resistance by expanding the class to include several new analogues of cisplatin, and putting these through clinical studies to broaden the different types of cancers against which they can be safely used.
 
Slow progress transitioning research into clinical practice
Despite these endeavors, platinum resistance remains a significant clinical challenge. Between 55 and 75% of women with ovarian cancer develop resistance to platinum based chemotherapy treatments. Significant research efforts have been dedicated to understanding this, but there has been relatively slow progress transitioning the research into effective clinical applications. According to Birrer, “the mechanism of platinum resistance from a molecular standpoint has not been well defined. It is likely to be heterogeneous, which means that each patient’s tumor may be slightly different. The hope is for targeted therapies and personalised medicine to have a chance of overcoming this, in that we could characterize the mechanism of the platinum resistance and apply and target therapy.”
 
2 theories of platinum resistance
In the video below, Birrer posits 2 theories to explain platinum resistance. “One suggests that under the influence of platinum the tumor changes and becomes resistant. Another suggests that there are 2 groups of cells to begin with. The vast majority of the tumor is sensitive, but there are small clusters of resistant cells. Once you kill the sensitive cells you have only the resistant cells left. Although these 2 theories have been around for about 25 years, there are no definitive data to suggest which theory is right. I have a personal scientific bias to think that the resistant cells are present at the time that we start the therapy. Being able to identify and characterize these cells upfront would be a radical breakthrough because then we would be able to target them at a time when they are only a small portion of the tumor,” says Birrer.
 
 
Takeaways

Saatchi is right; for decades ovarian cancer treatment has been wanting, but studies we describe in part-2 of this Commentary suggest that the tide might be turning for people living with ovarian cancer. So don't miss part-2 next week!
 
 
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Franca Esposito

Professor of Biochemistry, School of Medicine, University of Naples Federico II

Franca Esposito is Professor of Biochemistry, School of Medicine, University of Naples Federico II, Italy.

After graduating in medicine at the University of Naples Federico II, Professor Esposito did her residency in Clinical Biochemistry and Molecular Biology at the same University. Formerly, a visiting scientist, Department of Biochemistry, University of Missouri, Columbia, USA and a post-doctoral assistant at the Department of Biochemistry and Molecular Biology, University of Cincinnati, USA.

At the School of Medicine, University of Naples Federico II, Professor Esposito is the Coordinator for Biochemistry courses and President of the BS degree course for Medical Laboratory Technicians.

Her research activity has focused on the study of the redox regulation of gene expression and effects of reactive oxygen species on the: i) activity of some transcription factors; ii) expression of cell cycle regulatory proteins and iii) regulation of mitogenic signal transduction.

Professor Esposito's present research activity includes the study of TRAP1, a novel antiapoptotic gene involved in the resistance to anticancer therapy. She is working on the validation of TRAP1 as a new biomarker and drug target candidate in multiple human cancers and chemoresistance.


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