Richard T. Penson, MD, Bradley J. Monk, MD, and Krishnansu S. Tewari, MD, weigh in on the changing landscape of the treatment of cervical cancer.
Cytological specimen showing cervical cancer specifically squamous cell carcinoma in the cervix. Tissue is stained with pap stain and magnified x200.
SOURCE: The Web site of the National Cancer Institute (http://www.cancer.gov).
Richard T. Penson, MD, MRCP, is an associate professor in the department of medicine at Harvard Medical School and clinical director of medical and gynecological oncology at Massachusetts General Hospital.
Q:We know that cisplatin and radiotherapy has been a standard of care in cervical cancer for over 2 decades. How do you think the treatment of cervical cancer has evolved over the last 5 years or so?
A:The report from Dueñas-González et al1showed that 2 drugs combined with radiotherapy are better than one, but there is a lot of toxicity with such a regimen, and the field is waiting for results from the OUTBACK study (NCT01414608), which is looking at cisplatin chemoradiation with and without #4 cycles of adjuvant paclitaxel and carboplatin, and there is another international study looking at paclitaxel/cisplatin concurrent treatment. We do think that 2 chemotherapies are better than one, but we only use cisplatin with radiation at the moment, because the toxicity of a gemcitabine/platinum combination is unacceptable. I have used gemcitabine/cisplatin maybe in at most 3 or 4 cases without incident, but these were carefully selected patients. We use a lot of 5-FU/cisplatin for recurrent cervical disease, and we use a lot of mitomycin C/5-FU for vulvar cancer. In terms of targeted therapy, we have not combined bevacizumab with cisplatin/radiation, but we have combined it with radiation in a phase II trial. We are also interested in erlotinib with cisplatin/radiation, but neither of these combinations are as yet a standard of care.
Richard T. Penson, MD, MRCP
Q:How has the role of VEGF receptor, EGFR, and other molecular pathways evolved in the treatment of cervical cancer?
A:In terms of combining cisplatin/paclitaxel or topotecan/paclitaxel with bevacizumab, the Tewari paper confirms that as a new standard.2About 40% of patients in the United States are getting one of those combinations right now, many receiving carboplatin/paclitaxel because of another RCT run by the Japanese Gynecological Group. Adding bevacizumab to cisplatin paclitaxel or carboplatin paclitaxel is now the standard. The main problem with this approach is that approximately 9% of patients in the Tewari study had either fistulas or gastrointestinal perforations. So there is a high and morbid complication rate and you have to select patients carefully.
As for cervical cancer in general, the VEGF / VEGFR pathway is big, but there have not been much data on the TKIs as yet. EGFR, on the other hand, has been a bit disappointing. Interest in EGFR has been eclipsed by data about the phosphatidylinositol (PI3) kinase pathway. This is currently the most exciting target, but other targets, such as AKT and MET, are also thought to be important.
We have a trial under way with trametinib and a PI3 kinase inhibitor, GSK2126458 (NCT01958112), and a lot of people are combining biologics in novel combinations for recurrent cervical cancer. Overall, we think about 40% of the patients have identifiable targets or mutations that are exploitable. Cervical cancer is very much what we call an oncogene-addicted tumor, like EGFR-driven lung cancer. It is possible that more than one-third of cervical cancer is like that and could be treated with oral medication as primary therapy. Accordingly, we do mutational testing when patients have incurable disease (ie, unresectable, refractory, or recurrent).
Q:What do you think have been some of the other promising developments in cervical cancer over the past year?
A:I think another key development has been the adoptive immunotherapy study presented by Hinrichs and colleagues at this year’s ASCO meeting; this is really big news, and there is a lot of interest in using this approach for patients with metastatic cervical cancer.3
Bradley J. Monk, MD, FACOG, FACS
Bradley J. Monk, MD, FACOG, FACS, is professor and director of the division of gynecologic oncology and vice chair of the department of obstetrics and gynecology at the University of Arizona Cancer Center in Phoenix, Arizona.
Q:How do you think the treatment of cervical cancer evolved over the last 5 years or so?
A:There has really been no evolution in the primary treatment of cervical cancer over the last 5 years; it’s all about educating people, and certainly treatment is generally based on stage and the condition of the patient. The standard remains chemotherapy in combination with radiotherapy for the primary treatment of locally advanced disease, as we have summarized previously.4
Q:Where do you see targeted therapies (eg, VEGFR- and EGFR-targeted agents) playing a role in the treatment of cervical cancer?
A:Last month, based on ourNew England Journal of Medicinepaper5, we received FDA approval and National Comprehensive Cancer Network (NCCN) Level 1 recommendation for bevacizumab in metastatic cervical cancer (combining bevacizumab with doublet chemotherapy).2,5So the big news in this regard is that standard treatment for metastatic disease is now triplet therapy, consisting of platinum, paclitaxel, and bevacizumab. By comparison, for all intents and purposes, anti-EGFR agents are of minimal or no activity in cervical cancer. In a randomized trial comparing an anti-VEGFR tyrosine kinase inhibitor, or TKI, versus an anti-EGFR TKI, the VEGFR-targeted agent (pazopanib) was shown to be more active than the EGFR-targeted therapy (lapatinib), and similar negative results have also been seen for the anti-EGFR antibody, cetuximab, in women with advanced and recurrent cervical cancer.6,7So, although EGFR is known to be over-expressed, the data have shown that it really is inactive and it has been largely a distraction in cervical cancer.
Q:What are some of the other promising approaches under investigation for cervical cancer treatment?
A:I believe the future of cervical cancer treatment is immunotherapy. The paper presented at this year’s ASCO meeting showing the utility of adoptive immunotherapy in cervical cancer has certainly been a significant development.3Another immunotherapy strategy that has shown promise is the Advaxis approach, which utilizes a live attenuated bacterial system,Listeria monocytogenes, to introduce HPV antigens and promote T-cell activation and antitumor immunity; the ongoing GOG-0265 trial is currently investigating this approach, so this is very exciting news from ASCO as well.8,9
Krishnansu S. Tewari, MD, FACOG, FACS
Krishnansu S. Tewari, MD, FACOG, FACS, is professor and director of research and principal investigator at NRG Oncology and GOG Legacy at University of California Irvine Medical Center. He is also director of the gynecologic oncology program at St. Joseph's Center for Cancer Prevention & Research, and director of continuing medical education at the department of obstetrics and gynecology at University of California, Irvine.
Q:We know that cisplatin/radiotherapy has been a standard of care in cervical cancer for over 2 decades. How do you think the treatment of cervical cancer evolved over the last 5 years or so?
A:For early-stage cervical cancer, more conservative surgery has been adopted, especially for women who wish to retain childbearing capacity. Otherwise, for early-stage cervical cancer (Federation of Gynecology and Obstetrics [FIGO] stages IA2-IB1), robotic radical hysterectomy with bilateral salpingectomy and bilateral pelvic lymph node dissection has become increasingly more common. For locally advanced cervical cancer (FIGO stages IB2-IVA), concurrent chemoradiation followed by high-dose rate brachytherapy remains the gold standard. Finally, for metastatic (FIGO stage IVB) and recurrent cervical cancer, the biggest breakthrough has come from Gynecologic Oncology Group Protocol 240, which studied the incorporation of anti-angiogenesis therapy using bevacizumab together with either cisplatin plus paclitaxel chemotherapy or topotecan plus paclitaxel chemotherapy.2This study demonstrated significantly improved overall survival without a significant deterioration in quality of life in women receiving chemotherapy plus bevacizumab, and led to the FDA approval of bevacizumab for advanced cervical cancer on August 14, 2014.
Q:What are some of the most promising targeted therapies currently under investigation for cervical cancer?
A:Currently, anti-angiogenesis drugs, such as bevacizumab as well as the anti-programmed death receptor 1 agent, nivolumab, are promising. Mammalian target of rapamycin inhibitors (mTORi) may also be active in some populations.
Q:How has the role of the VEGFR, EGFR, and other molecular pathways evolved in the treatment of cervical cancer?
A:Anti-VEGFR therapy using pazopanib has been shown to be superior to anti-EGFR therapy using lapatinib in a randomized phase II trial of women with recurrent cervical cancer.6Overall, the most important pathway remains the VEGF-dependent angiogenesis pathway. The mTOR pathway may also be important in select populations.