In the county of Stockholm, between 1970 and 2002, we have previously reported a 3‐fold parallel increase in the incidence of tonsillar squamous cell carcinoma (SCC) and the proportion of human papillomavirus (HPV) positive tonsillar SCC. Here, we have followed the above parameters in all patients (n = 120) diagnosed with tonsillar SCC during 2003–2007 in the same area, and also in correlation to our previous data. Ninety‐eight pretreatment biopsies were available and presence of HPV DNA and HPV‐16 E6 and E7 RNA were tested by polymerase chain reaction (PCR) and RT‐PCR. Incidence data were obtained from the Swedish Cancer Registry. Data reported from 1970 to 2002 were also obtained for comparison. HPV DNA was present in 83 of 98 (85%) of the tonsillar SCC biopsies from 2003 to 2007 and 77 of these were HPV‐16 positive. HPV‐16 E6 and E7 RNA were found in 98% of 52 analyzed HPV‐16 positive cases. The proportion of HPV‐positive cancers had significantly increased both from 1970 to 2007 (p < 0.0001) as well from 2000 to 2007 (p < 0.01), with 68% (95% confidence interval (CI), 53–81) 2000–2002; 77% (95% CI, 63–87) 2003–2005; and 93% (95% CI, 82–99) 2006–2007. The incidence rate of HPV‐positive tumors almost doubled each decade between 1970 and 2007, in parallel with a decline of HPV‐negative tumors. In conclusion, the incidence of HPV‐positive cancers is still increasing in the County of Stockholm, suggesting an epidemic of a virus‐induced carcinoma, with soon practically all tonsillar SCC being HPV positive, as in cervical cancer. © 2009 UICC

Smoking and alcohol are well‐known etiological factors in tonsillar cancer. However, as in cervical cancer, human papillomavirus (HPV) is currently found in a sizable proportion of tonsillar cancer. Recent reports from the U.S. and Finland show an increase in the incidence of tonsillar cancer, without a parallel rise in smoking and alcohol consumption. This study investigates whether the incidence of tonsillar cancer has also changed in Sweden and whether a possible explanation of the increase is a higher proportion of HPV‐positive tonsillar cancer. The incidence of tonsillar cancer between 1970 and 2002 in the Stockholm area was obtained from the Swedish Cancer Registry. In parallel, 203 pretreatment paraffin‐embedded tonsillar cancer biopsies taken during 1970–2002 from patients in the Stockholm area were tested for presence of HPV DNA by PCR. The incidence of tonsillar cancer increased 2.8‐fold (2.6 in men and 3.5 in women) from 1970 to 2002. During the same period, a significant increase in the proportion of HPV‐positive tonsillar cancer cases was observed, as it increased 2.9‐fold (p < 0.001). The distribution of HPV‐positive cases was 7/30 (23.3%) in the 1970s, 12/42 (29%) in the 1980s, 48/84 (57%) in the 1990s and 32/47 (68%) during 2000–2002. We have demonstrated a highly significant and parallel increase both in the incidence of tonsillar cancer and the proportion of HPV‐positive tumors. Hence, HPV may play an important role for the increased incidence of tonsillar cancer. This should definitely influence future preventive strategies as well as treatment for this type of cancer.

A total of 308,036 women were selected from the European Prospective Investigation into Cancer and Nutrition (EPIC) study to evaluate the association between tobacco smoking and the risk of cervical intraepithelial neoplasia of grade 3 (CIN3)/carcinoma in situ (CIS) and invasive cervical cancer (ICC). At baseline, participants completed a questionnaire and provided blood samples. During a mean follow‐up time of 9 years, 261 ICC cases and 804 CIN3/CIS cases were reported. In a nested case–control study, the baseline sera from 609 cases and 1,218 matched controls were tested for L1 antibodies against HPV types 11, 16, 18, 31, 33, 35, 45, 52, 58, and antibodies against Chlamydia trachomatis (CT), and Human Herpes Virus 2 (HHV‐2). Cervical samples were not available for HPV‐DNA analysis in this study. Multivariate analyses were used to estimate associations between smoking and risk of CIN3/CIS and ICC in the cohort and the case–control studies. In the cohort analyses smoking status, duration and intensity showed a two‐fold increased risk of CIN3/CIS and ICC, while time since quitting was associated with a two‐fold reduced risk. In the nested case–control study, consistent associations were observed after adjustment for HPV, CT and HHV‐2 serostatus, in both HPV seronegative and seropositive women. Results from this large prospective study confirm the role of tobacco smoking as an important risk factor for both CIN3/CIS and ICC, even after taking into account HPV exposure as determined by HPV serology. The strong beneficial effect of quitting smoking is an important finding that will further support public health policies for smoking cessation.

The frequency of human papilloma virus (HPV) and its influence on clinical outcome was analyzed retrospectively in pre‐treatment paraffin embedded biopsies from 110 patients with tongue cancer. The presence of HPV DNA was examined in 85 mobile tongue tumors and 25 base of tongue tumors by a polymerase chain reaction (PCR) with 2 general primer pairs, GP5+/6+ and CPI/IIG. When HPV‐DNA was found, HPV‐type specific primers and direct sequencing were used for HPV sub‐type verification. Twelve of 110 (10.9%) samples were HPV‐positive; 9 for HPV‐16, 1 for HPV‐33, 1 for HPV‐35 and 1 could not be analyzed because of shortage of DNA. HPV was significantly more common in base of tongue tumors (10/25, 40.0%) compared to tumors of the mobile tongue (2/85, 2.3%). The influence of HPV on clinical outcome in mobile tongue cancer could not be studied, due to that HPV was present in too few cases. Of the 19 patients with base of tongue cancer that were included in the survival analysis, however, 7 patients with HPV‐positive base of tongue cancer had a significantly favorable 5‐year survival rate compared to the 12 HPV‐negative patients. In conclusion, HPV is significantly more common in base of tongue cancer than in mobile tongue cancer, and has a positive impact on disease‐specific survival in patients with base of tongue cancer.

In addition to HPV, high parity and hormonal contraceptives have been associated with cervical cancer (CC). However, most of the evidence comes from retrospective case-control studies. The aim of this study is to prospectively evaluate associations between hormonal factors and risk of developing cervical intraepithelial neoplasia grade 3 (CIN3)/carcinoma in situ (CIS) and invasive cervical cancer (ICC). We followed a cohort of 308,036 women recruited in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study. At enrollment, participants completed a questionnaire and provided serum. After a 9-year median follow-up, 261 ICC and 804 CIN3/CIS cases were reported. In a nested case-control study, the sera from 609 cases and 1,218 matched controls were tested for L1 antibodies against HPV types 11,16,18,31,33,35,45,52,58, and antibodies against Chlamydia trachomatis and Human herpesvirus 2. Multivariate analyses were performed to estimate hazard ratios (HR), odds ratios (OR) and corresponding 95% confidence intervals (CI). The cohort analysis showed that number of full-term pregnancies was positively associated with CIN3/CIS risk (p-trend = 0.03). Duration of oral contraceptives use was associated with a significantly increased risk of both CIN3/CIS and ICC (HR = 1.6 and HR = 1.8 respectively for ≥15 years versus never use). Ever use of menopausal hormone therapy was associated with a reduced risk of ICC (HR = 0.5, 95%CI: 0.4–0.8). A non-significant reduced risk of ICC with ever use of intrauterine devices (IUD) was found in the nested case-control analysis (OR = 0.6). Analyses restricted to all cases and HPV seropositive controls yielded similar results, revealing a significant inverse association with IUD for combined CIN3/CIS and ICC (OR = 0.7). Even though HPV is the necessary cause of CC, our results suggest that several hormonal factors are risk factors for cervical carcinogenesis. Adherence to current cervical cancer screening guidelines should minimize the increased risk of CC associated with these hormonal risk factors.