ABSTRACT
Bevacizumab has demonstrated significant benefit in recurrent ovarian, fallopian tube and peritoneal cancer (OC), but its optimal position within the sequence of systemic therapies remains controversial. Since rebound progression after bevacizumab has been observed in other cancers, and because bevacizumab is incorporated in several regimens used in the recurrent setting, the duration of treatment may impact survival. We sought to identify whether earlier bevacizumab exposure is associated with prolonged bevacizumab therapy and survival by conducting a multi-institution retrospective study of recurrent OC patients treated with bevacizumab from 2004-2014. Multivariate logistic regression identified factors associated with receiving more than six bevacizumab cycles. Overall survival by duration and ordinal sequence of bevacizumab therapy were evaluated using logrank testing and Cox regression. In total, 318 patients were identified. 89.1% had stage III or IV disease; 36% had primary platinum resistance; 40.5% received two or fewer prior chemotherapy regimens. Multivariate logistic regression demonstrated that primary platinum sensitivity (Odds Ratio (OR) 2.34, p = 0.001) or initiating bevacizumab at the first or second recurrence (OR 2.73, p < 0.001) were independently associated with receiving more than six cycles of bevacizumab. Receiving more cycles of bevacizumab was associated with improved overall survival whether measured from time of diagnosis (logrank p < 0.001), bevacizumab initiation (logrank p < 0.001), or bevacizumab discontinuation (logrank p = 0.017). Waiting one additional recurrence to initiate bevacizumab resulted in a 27% increased hazard of death (Hazard Ratio (HR) 1.27, p < 0.001) by multivariate analysis. In conclusion, patients with primary platinum sensitive disease who received fewer prior lines of chemotherapy were able to receive more cycles of bevacizumab, which was associated with improved overall survival. Survival worsened when bevacizumab was initiated later in the ordinal sequence of therapies.
ABSTRACT
OBJECTIVE: To evaluate patterns of recurrence for ovarian, fallopian tube, and primary peritoneal cancer patients undergoing extended treatment with bevacizumab (BEV). METHODS: A retrospective review of patients with primary ovarian, fallopian tube, or peritoneal cancer treated with BEV alone or in combination with other chemotherapy from 2001 to 2011 was performed. Qualified patients were identified by chemotherapy records. Electronic medical records, labs, and imaging reports were reviewed and abstracted. RESULTS: Of 108 patients identified, 89 patients met study criteria by having disease progression either during treatment with BEV or after discontinuing BEV without initiating any other treatment. Patients on extended BEV therapy (>12 cycles) were more likely to recur in extra-visceral sites (p=0.04), especially in lymph nodes (p=0.0002), and presented with fewer symptoms at time of recurrence (p=0.02), compared to patients who had received ≤ 12 cycles. CA-125 becomes less reliable for the detection of recurrent disease with extended BEV therapy (p=0.03 for ≤12 cycles vs. p=0.08 for >12 cycles). Radiology was superior to CA-125, symptom, and physical exam, in detecting recurrence with extended BEV therapy (all p<0.0001). CONCLUSIONS: Extended treatment with BEV in ovarian, fallopian tube, and peritoneal cancers results in alterations in the patterns of recurrence. Radiologic imaging is more reliable than CA-125, symptoms, or physical exam, in identifying recurrent disease in patients undergoing BEV treatment. As novel targeted therapies continue to be employed, guidelines for gynecologic cancer surveillance must continue to be reexamined.
