麻豆传媒

PHOENIX -- Adjuvant chemotherapy was not associated with better overall survival (OS) for patients with advanced stage low-grade serous ovarian carcinoma undergoing primary cytoreductive surgery, according to an observational study presented here.

There was no difference in OS between patients who did and did not receive adjuvant chemotherapy, with 4-year OS rates of 77.5% and 76.1%, respectively, reported Dimitrios Nasioudis, MD, gynecologic oncology fellow at the University of Pennsylvania in Philadelphia.

Stratifying patients by residual disease status, there was no survival benefit with adjuvant chemotherapy whether patients achieved complete gross resection or had gross residual disease, Nasioudis said in a poster presentation at the annual meeting of the

"On the contrary, patients with gross residual disease had worse outcomes compared to those who had complete gross resection," Nasioudis added. Specifically, the 179 patients with gross residual disease had worse OS compared to those with complete gross resection (median OS 69.82 months versus 90.32 months, P<0.001). This pattern was maintained after controlling for confounders (HR 2.25, 95% CI 1.58-3.21).

Among patients who achieved complete gross resection, those who received adjuvant chemotherapy had 4-year OS rates of 85.5% vs 79.5% (P=0.60) for those who didn't receive adjuvant chemotherapy. Those patients with gross residual disease had OS rates of 63.1% and 66.3%, respectively (P=0.85).

Gynecologic oncologist Lisa Barroilhet, MD, MS, of University of Wisconsin in Madison, commented that while residual disease is an important prognostic factor and underscores the importance of aggressive surgical debulking, it doesn't clarify "what we should be doing in terms of adjuvant therapy,"

"It does not seem that chemotherapy is the best thing for these patients since it does not necessarily improve overall survival, but can we clarify other mechanisms of adjuvant therapy for newly diagnosed advanced stage low-grade serous ovarian cancer patients?" she asked at the presentation.

Barroilhet suggested that the randomized phase III trial of paclitaxel/carboplatin followed by maintenance letrozole versus letrozole monotherapy in the same population of patients could bring some clarity to this issue.

"It will be years before the overall survival data [from this study] is mature, but I think this is a very exciting study that we all should be accruing to in order to better answer this question," she said. "I think none of us feels fabulous giving cytotoxic chemotherapy to these patients."

For this study, Nasioudis and colleagues accessed data from the National Cancer Database to identify 618 patients with grade 1 tumors and stage II-IV disease. These patients underwent primary cytoreductive surgery, and had known data on the results of the surgery and the administration of adjuvant chemotherapy. Patients were excluded from the study if they had received neoadjuvant chemotherapy.

Of those patients, 81.1% received adjuvant chemotherapy, 3.6% received anti-estrogen hormonal therapy, and the remaining 15.3% did not receive any adjuvant therapy at all. The median follow-up of these patients was 48 months.

Even after controlling for patient age, presence of comorbidities, disease stage and residual disease status, administration of adjuvant chemotherapy was not associated with better OS (HR 0.87, 95% CI 0.55-1.38).

Nasioudis acknowledged that study limitations included the absence of central pathology review and lack of data of tumor relapse, cause of death, and the composition of the chemotherapy regimen administered.

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