Cathy Eng, MD at Vanderbilt University Medical Center discusses Anal cancer's first randomized trial for inoperable disease sets the treatment standard
Patients with inoperable anal cancer, a rare condition, have not had a regular treatment so far; palliative care was the norm for them. Now the Journal of Clinical Oncology is releasing findings from InterAAct, the first international prospective randomized trial in advanced anal cancer. In 91 patients the study compared two different chemotherapy therapies. The primary outcome, Objective response rate (ORR), was the same between treatments. The ORR for cisplatin plus 5-fluorouracil (5FU) in carboplatin plus paclitaxel was 57 per cent versus 59 per cent. Cisplatin-5FU, however, was associated with substantially greater adverse effects (62 percent ) compared to carboplatin-paclitaxel (36 percent). Compared to cisplatin-5FU (12.3 months), carboplatin-paclitaxel was also associated with increased overall survival (20 months).
Anal cancer is rare and constitutes less than 3 per cent of all gastrointestinal cancers. Advanced, inoperable anal cancer is much rarer, comprising about 10 percent of all cases. The prognosis for these patients is low, with average survival rates of around 30 per cent for five years.
The research enrolled 91 patients in Australia, Germany , Norway, the United Kingdom , and the United States from December 2013 through November 2017. Because of the disease 's unusual nature, a global network of investigators was required to develop and perform tests for patients with metastatic anal cancer, provide patients with access to these new therapies, and enroll patients in a timely fashion. To achieve those goals, the International Rare Cancers Initiative (IRCI) created the Anal Cancer Working Group, a global collaboration network.
Formed in 2011, IRCI's founding members include the United States National Cancer Institute, the UK National Institute for Health Care, Cancer Research UK and the European Association for Cancer Research and Treatment. Subsequently all joined the French National Cancer Institute, Canadian Cancer Trials Group, Japan Clinical Oncology Group, and Australia's Clinical Oncology Society.
In the U.S., the ECOG-ACRIN Cancer Research Group led the trial through its National Clinical Trials Network, with funding from the National Cancer Institute ( NCI). The NCI is a member of the National Health Institutes.
Patients who had not previously undergone systemic chemotherapy for locally recurring inoperable or metastatic anal cancer were eligible for the InterAct trial. The 91 patients involved in the study were randomly allocated one-to-one: 46 patients receiving 60mg / m2 (day 1) 5FU 1000mg / m2 (day 1-4) intravenous cisplatin every 21 days and 45 patients receiving carboplatin (AUC=5, day 1) paclitaxel (80mg / m2 days 1, 8, 15) every 28 days. For all patients the median follow-up was 28.6 months. Patients stayed on medication until worsening of illness, intolerable toxicity or removal of consent.