In cervical cancer, the high risk HPV genotypes according to IARC are well described as a cause for cancer. Less is known about the impact of multiple genotypes in cancer progression and also on accompanying low risk types. With refined methods that are now available, substantially more genotypes can be included and evaluated for prognostic relevance.
128 cervical cancer cases, treated with primary radiotherapy, were included in the study. Genotyping was performed on FFPE sample DNA with the Anyplex II HPV28 (Seegene) detecting 28 different genotypes, both high and low risk types.
Results could be obtained from 121 of 128 samples. In total, 82% (99/121) were positive for HPV. HPV-16 was the most common genotype (n = 44) followed by HPV-18 (n= 11). Single infections were present in 82 cases and multiple infections in 17. Tumors with multiple infections were in general composed of two or more high risk types (n= 15), with 2 exceptions; HPV33+HPV42 and HPV56+ HPV53.
When comparing tumors with one genotype to tumors holding two or more genotypes; the overall recurrence-rate was 25.9% and 52.9% respectively (Pearson chi-square; P = 0.027). Distant recurrences were highly significantly (Pearson chi-square; P = 0.001) associated with presence of multiple HPV-genotypes 47.1% versus 12.9%. This group also had a worse cancer-specific survival rate (log-rank test; P = 0.023) compared to patients with tumors with one HPV genotype present.
Tumors containing HPV18 were associated with higher recurrence rate and more loco-regional recurrences compared to non-HPV 18 holding tumors (Pearson chi-square; P = 0.037 and 0.027). However, no significant associations between prognosis and individual HPV-types or groups of HPV-types were found.
Cervical cancer treated with primary radiotherapy (external beam therapy and brachytherapy) and positive for multiple HPV-strains is associated with more recurrences as well as worse prognosis (cancer-specific survival rate) compared with cases containing single strain HPV.