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Clinical factors affecting response to bevacizumab in metastatic colon cancer American Journal of Therapeutics


Purpose: Bevacizumab (BZ) combined with first line chemotherapy (CC) has shown good clinical

outcomes in metastatic colorectal cancer (mCRC). Overall survival (OS) and/or progression free

survival in mCRC patients receiving BZ with or without 5FU-based CC is thought to be affected

by clinical and morphological factor(s).

Patients and Methods: We reviewed retrospective medical records of all consecutive mCRC patients

treated with BZ with or without CC at tertiary care center between 2003 and 2009 out of which149

patients (m 5 77, f 5 72) were eligible.

Results: Our study population had a mean age at diagnosis of 63.5 years (SD 5 11) with median

follow-up period of 19.4 months. On initial radiological evaluation following BZ therapy, 56 patients

(m 5 31, f 5 25) had complete or partial response categorized as “early responders.” Remaining

patients (m 5 46, f 5 47) who were either stable or showed progressive disease were categorized as

“non-responders.” Fifty percent among early responders and 60% among non-responders [relative risk

(RR) 0.67 (95% confidence interval (CI), 0.43–1.06)] demonstrated disease progression on follow up.

There was a slightly better OS among early responders compared to non-responders (median 21.5

months days versus 16.8 months, P 5 0.07). Cox regression analysis suggested male sex (RR 0.65,

95% CI, 0.43–0.98), hematochezia (RR 0.63, 95% CI, 0.4–0.98), resectable primary tumor (RR 0.42, 95%

CI, 0.24–0.72) and resectable metastatic mass (RR 0.32, 95% CI, 0.14–0.74) were found to be associated

with longer OS. Abdominal pain (RR 1.76, 95% CI, 1.1–2.8), accompanying diabetes (RR 1.76, 95% CI,

1.09–2.85), and unexplained weight loss (RR 2.73, 95% CI, 1.73–4.29) were associated with poor OS.

Conclusions: Better OS among mCRC patients with resectable primary and metastatic tumors was

seen. This is the first study to demonstrate slightly better outcome in males and negative influence of

diabetes on outcome in mCRC treated with BZ.

Author List

Rezwan Islam, MD, FACP,1 Rafiullah Khan, MD,*,2 Asad Ali, MD,3 Vidya Kollu, MD,4 TramAnh Phan, MD,5 Po-Huang Chyou, PhD,5 James K. Burmester, PhD,6 and Muhammad G. Kibriya, MD, PhD7


Vidya Kollu MD Assistant Professor in the Medicine department at Medical College of Wisconsin
jenkins-FCD Prod-299 9ef562391eceb2b8f95265c767fbba1ce5a52fd6