The study found that both patient- and treatment-related factors contributed to noncompliance.
Deviation from treatment guidelines for women undergoing interval debulking surgery for advanced epithelial ovarian cancer resulted in a significantly lower 5-year overall survival (OS) compared with results in those who remained treatment compliant, according to a study in the journal Cancer Reports.1
“One of the primary treatment strategies for advanced epithelial ovarian cancers includes neoadjuvant chemotherapy (NACT) followed by interval debulking surgery (IDS) and adjuvant chemotherapy,” wrote the authors from Tata Memorial Hospital in Mumbai, India.
The study comprised 182 women diagnosed with advanced epithelial ovarian cancer (stages IIIC-IV) who underwent IDS at the hospital between October 2012 and September 2013.
The standard chemotherapy regimen included three to four cycles of taxanes and platinum as combination chemotherapy. The chemotherapeutic agents given were paclitaxel 175 mg/m2 and carboplatin at a dose of area under the curve 5‐6 every 3 to 4 weeks.
At the end of the third cycle, chemoresponse in the patients was assessed with clinical examination, assessment of cancer antigen 125 (CA-125) levels, and computed tomography (CT) scans.
Optimal response to chemotherapy was defined as radiological evidence of no or minimal ascites, absence of pleural effusion, a decrease in gross abdominal disease by at least 50% of the initial disease at presentation, and reduction in CA-125 levels.
All patients met these criteria and subsequently underwent IDS.
Optimal cytoreduction was defined as no residual disease (R0) or residual disease < 1 cm (R1) at the completion of surgery. Two to three cycles of adjuvant chemotherapy (platinum and taxane) were then scheduled within 3 to 4 weeks of surgery.
All patients had a clinical examination and CA-125 testing every 3 to 4 months for the first 2 years after surgery, and every 6 months for the next 3 years. Radiological investigations were limited to those in whom disease recurrence was suspected.
At each phase of treatment, the investigators documented treatment deviations, which were characterized as deviations from the above‐mentioned protocol, whether treatment- or patient-related.
During the chemotherapy phases, reasons for protocol deviation were divided into four categories: administration of single-agent chemotherapy instead of two agents; administration of more than four or less than three cycles of chemotherapy; longer than 6 weeks between chemotherapy cycles; and administration of nonplatinum‐ and/or taxane‐based chemotherapy.
During the IDS phase, a delay of more than 6 weeks for surgery after deciding to perform IDS was considered a deviation.
Likewise, as the number of deviations increased, there was a reduction in the OS: 58.2% for no deviation vs. 11.1% for three deviations (P = 0.004).
The most common reason for treatment deviation during all phases of treatment was unknown reason (n = 37), followed by single-agent chemotherapy (29), logistic issues such as lack of beds (20), excessive therapy cycles (18), treatment-related toxicity (10), and non-paclitaxel and carboplatin chemotherapy (8).
Deviation or noncompliance with treatment resulted in significantly reduced 5-year OS compared to compliant patients: 34.4% vs 58.2% (P = .001). This reduction also retained its significance in multivariate analysis (P = 0.024).
“This study paves way to improve compliance in low‐ and medium‐resource countries, which can possibly predict good outcomes before considering expensive drugs or advanced technologies for treatment,” wrote the authors.