Abstract
Objective: Previous investigators have reported higher HPV type 16 antibody positivity among cervical cancer patients than among healthy women. The objective of this study was to determine the association of HPV 16 antibody levels with the stage of cervical cancer. Methods: Pretreatment tumor biopsies and sera were obtained from 137 newly diagnosed cervical cancer patients residing in Mexico. Using peptide ELISA and radioimmunoprecipitation assay (RIPA), HPV 16 E6- and E7-specific antibodies were measured. Results: By ELISA, elevated antibody titers to HPV 16 E6 and E7 were detected in 16.8 and 32.8% of the women, respectively. While sera positivity did not differ by disease stage, the mean absorbance in the E7-positive sera was 0.42, 0.62, 0.91, and 0.81 for stages I to IV, respectively. Using RIPA, anti-E6 and E7 positivity was demonstrated in 46.7 and 38.7% of the females, respectively. Although no difference across disease stage was detected for E6, increasing proportions of positivity to E7 with stage of disease was detected. The rates for increasing disease stage were 0.14, 0.37, 0.40, and 0.67. Sera from the 6-month postradiation follow-up examinations of a small group of patients demonstrated a statistically significant decrease in antibody positivity from pretreatment positivity to HPV 16 E6 (n= 14;P= 0.01) and HPV 16 E7 (n= 20;P= 0.0001) using ELISA. Conclusions: These data suggest that HPV 16 E7 antibody positivity may be associated with stage of cervical cancer. Such immune parameters may be applicable to disease staging, monitoring of recurrence and, perhaps, diagnosis. Further investigation into the relationship of HPV 16 E6 and E7 antibodies with stage of cervical cancer and response to therapy is warranted.