Sentinel node mapping
The rationale for sentinel node mapping is that if one or more sentinel lymph nodes is/are negative for malignancy, then the other regional lymph nodes will also be negative. This would thereby avoid the need for a complete lymph node dissection and its resultant complications, including chronic lymphedema. Much of the work pioneering this strategy has been in breast cancer and melanoma, but data are rapidly emerging for these techniques in gynecologic malignancies.
Candidates for sentinel lymph node biopsy for vulvar cancer include those with a lesion more than 1mm in depth, a tumor less than 4 cm in size, and no obvious metastatic disease on exam or preoperative imaging. Additionally, recommendations have been made regarding case volume in order to achieve limited numbers of false-negative results and to maintain competency. In the study by Van der Zee et al. of 403 patients (623 groins) who underwent sentinel node procedures, the false-negative rate was 0-2%. The overall survival rate was 97% at 3 years (J Clin Oncol. 2008 Feb 20;26[6]:884-9). However, a more recent data from the Gynecologic Oncology Group (GOG 173) showed a slightly higher false-negative rate of 8% (J Clin Oncol. 2012 Nov 1;30[31]:3786-91). Overall survival data are pending from this study.
While sentinel lymph node mapping for endometrial cancer has been feasible for many years and has been well described, the questioned role of completed lymphadenectomy for early-stage endometrial cancer has led to a resurgence of interest in these techniques. While blue dye and radiolabeled tracer methods have historically been the most popular mapping solutions, the advent of endoscopic near-infrared imaging, with its higher sensitivity and good depth penetration, has added options. Indocyanine green fluorescence can be easily detected during robotic surgery and as experience with these techniques increase, successful mapping and sensitivity will increase.
Genetics
While hereditary cancer syndromes have been recognized for many years, detecting the genetic mutations that may increase an individual’s risk of developing a malignancy were not elucidated until the early 1990s. In gynecologic oncology, the most commonly encountered syndromes involve mutations in BRCA1 and BRCA2 and hereditary non–polyposis colorectal cancer, which causes mutations in DNA mismatch-repair genes and increase the risk of endometrial and ovarian cancer.
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The SGO recently published a statement on risk assessment for inherited gynecologic cancer predispositions. In this statement “the evaluation for the presence of a hereditary cancer syndrome enables physicians to provide individualized and quantified assessment of cancer risk, as well as options for tailored screening and preventions strategies that may reduce morbidity associated with the development of malignancy” (Gynecol Oncol. 2015 Jan;136[1]:3-7). Beyond risk-reducing salpingo-oophorectomy, therapeutic strategies targeting patients with germline mutations have been developed (PARP inhibitors in BRCA-mutated women with ovarian cancer).
In August 2015, ASCO released an updated policy statement on genetic and genomic testing for cancer susceptibility and highlighted five key areas: germ-line implications of somatic mutation profiling; multigene panel testing for cancer susceptibility; quality assurance in genetic testing; education for oncology professionals; and access to cancer genetic services.
Antiemetics
Rounding out ASCO’s “Top 5 advances in 50 years of Modern Oncology” was the improvement in patients’ quality of life from supportive therapies, in particular antinausea medications.
Several of the agents commonly used in gynecologic oncology rate high (cisplatin) to moderate (carboplatin, cyclophosphamide, doxorubicin, ifosfamide) with regards to emetogenicity. The advent of 5-HT3 receptor antagonists (for example, ondansetron) has significantly improved the quality of life of patients undergoing cytotoxic chemotherapy. In addition to improving quality of life, the decrease in nausea and vomiting can also decrease life-threatening complications such as dehydration and electrolyte imbalance. Both ASCO and the National Comprehensive Cancer Network both have guidelines for the management of nausea and vomiting in patients undergoing chemotherapy.
Throughout 2016, Ob.Gyn. News will celebrate its 50th anniversary with exclusive articles looking at the evolution of the specialty, including the history of contraception, changes in gynecologic surgery, and the transformation of the well-woman visit. Look for these articles and more special features in the pages of Ob.Gyn. News and online at obgynnews.com.
Dr. Gehrig is professor and director of gynecologic oncology at the University of North Carolina, Chapel Hill. Dr. Clarke-Pearson is the chair and the Robert A. Ross Distinguished Professor of Obstetrics and Gynecology, and a professor in the division of gynecologic oncology at UNC. They reported having no relevant financial disclosures.