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.

Numerous reports have shown that the incidence for oropharyngeal cancer is increasing and that human papillomavirus (HPV) is a risk factor. However, few studies have investigated the specific subsites of the oropharynx. Following our previous research on tonsillar cancer, we assessed the increase in the incidence of base of tongue cancer and the prevalence of HPV in this disease. Between 1998 and 2007, 109 patients were diagnosed for base of tongue cancer in Stockholm county. Ninety‐five paraffin‐embedded diagnostic tumor biopsies from patients were obtained and tested for HPV, both by general HPV PCR and HPV‐16/HPV‐33 type‐specific PCR. Expression of HPV‐16 RNA was analyzed to confirm E6 and/or E7 expression. Incidence data were obtained from the Swedish Cancer Registry. An overall increase in the incidence of base of tongue cancer from 0.15/100,000 person‐years during 1970–1974 to 0.47/100,000 person‐years during 2005–2007 was found in Sweden. The prevalence of HPV in base of tongue cancer in Stockholm county increased from 58% during 1998–2001 to 84% during 2004–2007 (p < 0.05). In the HPV‐positive tumors, HPV‐16 dominated (86%) but interestingly, HPV33 was detected in as many as 10%. E6 and/or E7 RNA were found in 85% of the samples tested. The incidence of base of tongue cancer, as well as the proportion of HPV‐positive tumors, has increased in Sweden during the study period, suggesting that HPV may contribute to this increase.

Human papillomavirus (HPV) is a causative factor for tonsillar squamous cell carcinoma (TSCC) and patients with HPV positive (HPV⁺) TSCC have a better clinical outcome than those with HPV negative (HPV⁻) TSCC. However, since not all patients with HPV⁺TSCC respond to treatment, additional biomarkers are needed together with HPV status to better predict response to therapy and to individualize treatment. For this purpose, we examined whether the number of tumor infiltrating cytotoxic and regulatory T-cells in TSCC correlated to HPV status and to clinical outcome. Formalin fixed paraffin embedded TSCC, previously analysed for HPV DNA, derived from 83 patients, were divided into four groups depending on the HPV status of the tumor and clinical outcome. Tumors were stained by immunohistochemistry and evaluated for the number of infiltrating cytotoxic (CD8⁺) and regulatory (Foxp3⁺) T-cells. A high CD8⁺ T-cell infiltration was significantly positively correlated to a good clinical outcome in both patients with HPV⁺ and HPV^- TSCC patients. Similarly, a high CD8⁺/Foxp3⁺ TIL ratio was correlated to a 3-year disease free survival. Furthermore, HPV⁺TSCC had in comparison to HPV⁻TSCC, higher numbers of infiltrating CD8⁺ and Foxp3⁺ T-cells. In conclusion, a positive correlation between a high number of infiltrating CD8⁺ cells and clinical outcome indicates that CD8⁺ cells may contribute to a beneficial clinical outcome in TSCC patients, and may potentially serve as a biomarker. Likewise, the CD8⁺/Foxp3⁺cell ratio can potentially be used for the same purpose.

PURPOSE: We performed an open-label randomized controlled phase III study comparing treatment outcome and toxicity between radiotherapy (RT) with concomitant cisplatin versus concomitant cetuximab in patients with locoregionally advanced head and neck squamous cell carcinoma (HNSCC; stage III-IV according to the Union for International Cancer Control TNM classification, 7th edition). MATERIALS AND METHODS: Eligible patients were randomly assigned 1:1 to receive either intravenous cetuximab 400 mg/m² 1 week before start of RT followed by 250 mg/m²/wk, or weekly intravenous cisplatin 40 mg/m², during RT. RT was conventionally fractionated. Patients with T3-T4 tumors underwent a second random assignment 1:1 between standard RT dose 68.0 Gy to the primary tumor or dose escalation to 73.1 Gy. Primary end point was overall survival (OS) evaluated using adjusted Cox regression analysis. Secondary end points were locoregional control, local control with dose-escalated RT, pattern of failure, and adverse effects. RESULTS: Study inclusion was prematurely closed after an unplanned interim analysis when 298 patients had been randomly assigned. At 3 years, OS was 88% (95% CI, 83% to 94%) and 78% (95% CI, 71% to 85%) in the cisplatin and cetuximab groups, respectively (adjusted hazard ratio, 1.63; 95% CI, 0.93 to 2.86; P = .086). The cumulative incidence of locoregional failures at 3 years was 23% (95% CI, 16% to 31%) compared with 9% (95% CI, 4% to 14%) in the cetuximab versus the cisplatin group (Gray’s test P = .0036). The cumulative incidence of distant failures did not differ between the treatment groups. Dose escalation in T3-T4 tumors did not increase local control. CONCLUSION: Cetuximab is inferior to cisplatin regarding locoregional control for concomitant treatment with RT in patients with locoregionally advanced HNSCC. Additional studies are needed to identify possible subgroups that still may benefit from concomitant cetuximab treatment.