Combining radiation therapy and concurrent chemotherapy postsurgery: promising results observed for high-risk endometrial cancer

A study published in the International Journal of Radiation Oncology reports results demonstrating that postsurgery radiation therapy combined with concurrent paclitaxel chemotherapy can be an effective treatment for patients with high-risk endometrial cancer. The study investigated the efficacy and toxicity of weekly concurrent chemoradiation in patients with stage III and IV endometrial cancer.

When caught in the early stages, endometrial cancer is treated with surgery alone. For individuals with a more advanced form of the disease who are at risk of more recurrences, treatment using concurrent radio- and chemo-therapy is carried out.

In total, 57 patients from 20 institutions in Korea were studied between January 2006 to March 2008. Patients were aged between 20 and 80 years old (average age: 52.2 years) and had International Federation of Gynecology and Obstetrics (FIGO) stage III or IV endometrioid adenocarcinoma.

Study participants had no history of previous surgery, chemotherapy or radiation therapy for cancer. Exclusion criteria included: patients with diagnoses of other cancers or severe infection requiring parenteral antibiotics; patients with a history of cardiac arrhythmia, congestive heart failure or myocardial infarction within the last 6 months; patients with uncontrolled infection, diabetes, hypertension or compromised cardiac, renal, liver or bone marrow functions.

Doses of 45.0–50.4 Gy of external pelvic radiation therapy (1.8–2.0 Gy daily, five-times a week) and 60 mg / m2 of paclitaxel administered intravenously for 3 h, once a week, for 6 weeks were administered. Radio- and chemo-therapy were initiated within 6 weeks of surgery, and the radiation therapy was started either 2 days before or 2 days after the first chemotherapy treatment.

In two patients, chemotherapy was stopped due to toxic events (one septic shock, and one persistent grade 4 neutropenia). One patient refused treatment and two withdrew before completing all six cycle of chemotherapy.

In total 52 patients were analyzed. Severe toxicities were mostly hematologic. Fifty-two episodes of grade III/IV neutropenia were seen, toxicity caused 98 cycles to be delayed and dose reductions of paclitaxel were carried out for eight patients.

Patients were followed-up for 5 years following treatment. In total, 19 patients (36.5%) experienced disease recurrence, 18 of which involved extrapelvic recurrence, and one had intrapelvic recurrence. After 5 years, nine patients (17.3%) had died from endometrial cancer. The 5-year survival rate was 63.5% and the overall survival rate was determined as 82.7%.

Jae-Hoon Kim (Gangnam Severance Hospital, Seoul, South Korea, and Yonsei University College of Medicine, Seoul, South Korea) , a co-author of the study commented that: “This study shows that concomitant radiation therapy and weekly paclitaxel chemotherapy is a reasonable treatment option for patients with advanced endometrial cancer that can reduce toxicity and reduce pelvic recurrence. These favorable results should be further evaluated in a larger, prospective, randomized, controlled study to validate this treatment approach.”

Source: Cho H, Nam BH, Kim SM et al. A Phase 2 trial of radiation therapy with concurrent paclitaxel chemotherapy after surgery in patients with high-risk endometrial cancer: a Korean Gynecologic Oncologic Group study. Int. J. Radiat. Oncol. Biol. Phys. 90(1), 140–146 (2014); American Society for Radiation Oncology press release