Dr. Kumar Abhishek, a SERMO Oncologist, shares insights from four interesting abstracts covering a variety of topics including long term outcome among survivors of childhood cancer to management of metastatic melanoma, head and neck cancer, and brain metastasis.
The very first study was a randomized comparison of dual immunotherapeutic approach with combination of Ipilimumab and Nivolumab compared either of the two agents alone. The combination therapy proved to be superior by all measured criterias – PFS (11.9 months in Nivo + Ipi vs 6.9 months in Nivo vs 2.9 months in Ipi alone) and ORR (57.6% in Nivo + Ipi vs 43.7% in Nivo vs 19% in Ipi alone). The toxicity was higher in the combined arm with all Grade 3-4 drug-related adverse events (AEs) occurred in 55.0%, diarrhea (9.3%), increased lipase (8.6%), increased alanine aminotransferase (8.3%), and colitis (7.7%). Drug-related AEs led to discontinuation of therapy in 36.4% of cases in the combination arm. Thus the higher efficacy comes at cost of a higher level of toxicity. The bigger question is my mind is the cost and feasibility of providing two highely expensive medicines for potentially indefinite period of time. We need to continue to ask the question of value in treatment and how do we rationalize the cost with efficacy of newer therapies.
The third abstract of the plenary session was presented by Dr. D’ Cruz from Mumbai, India. This study was a single institutional randomized controlled trial of elective versus therapeutic neck dissection in the treatment of early stage squamous cell carcinoma of the oral cavity. 500 patients with T1/T2 and N0 oral cancers were randomized to undergo resection of the primary tumor with or without level I-III neck dissection. Early LN dissection at the time of oral surgery lead to a 12% improvement OS at 3 years. The limitation of the study was the lack of information regarding adjuvant treatment of patients in either arms. Thus patients on the surveillance arm who had high risk feature (deep tumors, lymphovascular invasion) could have potentially benefited from adjuvant radiation thus reducing the margin of benefit in OS.
NCCTG N0574 (Alliance) was a phase III randomized trial which looked at the decline in cognitive function in patients who receive whole brain radiation therapy (WBRT) in addition to radiosurgery (SRS) for 1 to 3 brain metastases when compared to radiosurgery alone. The results revealed WBRT no improvement in OS when combined with radiosurgery in eligible patients. Addition of WBRT led to a worsening of neurocognitive function. The limitation of the study is that the rate of control of systemic disease was not accounted for and thus patients who have progression of systemic disease are not likely to see improved survival based on treatment of disease in the brain only. This would negate the potential survival benefit that could be seen with addition of WBRT to radiosurgery. The persistent detriment of neurocognitive function in this study is in contradiction with other studies. A phase III RCT by Lei et al (JCO 2007) had shown an actual improvement in neurocognitive function in patients who live beyond 12 months and that was due to reduction in disease progression in the brain. Thus WBRT should still be considered in approriate patients with brain metastasis.
Kumar Abhishek is a board certified Hematologist-Medical Oncologist. He is employed by a large regional health system in Richmond, VA and works with the multi-specialty medical group. Dr. Abhishek received his medical degree from the University College of Medical Sciences located in Delhi, India, and completed his internal medicine residency from Carilion Clinic in Roanoke, Va. He also finished a fellowship in hematology and medical oncology from Saint Louis University in St. Louis, MO. Before starting his training in hematology and oncology, he worked as a clinical instructor and hospitalist at Allegheny General Hospital in Pittsburgh, Pa., and Chippenham Johnston-Willis Hospital in Richmond, Va.