Significance of multiple HPV infection in cervical cancer patients and its impact on treatment response.

Human papilloma virus (HPV) is the major cause of invasive cervical cancer (ICC). The study aim was to determine the prevalence of HPV genotypes and to correlate HPV types with response to radiotherapy. A total of 43 cervical biopsies collected from sequentially enrolled patients were analyzed by DNA amplification with MY09/MY11 primers and sequenced to determine the HPV genotype. Samples with multiple infections were resolved by multiplex PCR, combined with array primer extension (APEX). HPV DNA was detected in 40 of 43 (93%) samples. Nine different HPVs, including the most common types -16 (53%) and -18 (13%) were detected. Other types were HPV 31, 33, 45, 52, 58, 66 and 68. Single HPV types were found in 33 of 40 samples (82%) and multiple types in 7 of 40 samples (18%). The following significant predictors were identified: a) HPV 58 was most significant (p=0.02), followed by HPV 18 (p=0.04) associated with lack of treatment response; b) tumor size (p=0.042) and treatment response (p=0.025) elicited association with HPV infection type; c) treatment failure were found to be nearly 5-fold higher in case of multiple infections than of single infection (57% versus 12%) (odds ratio = 9.66; 95% CI 1.6-6.00). d) Multiple HPV infections correlated most prominently with lack of treatment compared with single type infection (p=0.005). Hence, patients with multiple infections, large tumor size, and HPV 58 and/or 18, are at risk of treatment failure and need to be followed for response and suitable inter-ventions done for a favorable outcome.