Squamous cell carcinoma of the penis: multivariate analysis of prognostic factors and natural history in monocentric study with a conservative policy.

BACKGROUND

Penile carcinoma is uncommon in Western countries. Here we report on a large series of patients with squamous cell carcinoma (SCC) of the penis, describing prognostic factors, survival and therapeutic results.

PATIENTS AND METHODS

From 1973 to 1993, 102 patients with invasive SCC of the penis were treated at the Institut Gustave-Roussy. Precancerous lesions and conditions associated with penis cancer were analyzed retrospectively. Survival curves were estimated by the Kaplan-Meier method, and groups were compared for outcome by the log rank test for univariate comparisons and by Cox's proportional hazards model for multivariate analysis.

RESULTS

The median age at onset was 58 years. Sixty-nine patients presented with Jackson's stage I disease, 17 with stage II and 15 with stage III. The interval between the manifestation of symptoms and the diagnosis was more than a year in 13.7% of cases. Precancerous lesions were found in 17 (16.6%) patients, and a history of phimosis was noted in 25 (24.5%). In situ and invasive carcinoma were observed together in 17 (16.6%) cases and dysplasia was associated with invasive carcinoma in eight (7.8%) further cases. Conservative treatment was administered whenever feasible. Interstitial brachytherapy was performed alone or associated with limited surgery (local excision or circumcision) in 72 (70.6%) patients. Of the 28 patients with a local relapse, nine have died of their neoplasms (32%) compared to 21 of 28 patients with lymph node relapse (75%). The median follow-up was 111 months. Disease-free survival, disease-specific survival and overall survival were, respectively, 56%, 72% and 63% at five years and 42%, 66% and 50% at 10 years. Age (P = 0.01), the N status (P < 0.00001) or palpable nodes (P < 0.0038), corpus involvement (P = 0.006) and a verrucous histology (P = 0.038) had significant prognostic relevance for survival in the univariate analysis whereas the performance status, T status and Broders' grade did not. In the multivariate analysis only two parameters, involvement of the corpus (P < 0.0001) and palpable nodes (P = 0.009), were singled out as being independent variables influencing survival. A subgroup of nine patients with verrucous histologies were distinguished by their freedom from node involvement. These patients had an excellent prognosis: all are alive and disease-free. Penile integrity was preserved during follow-up in 54 patients (52.9%), 31 of whom are still alive. Of 72 patients treated by a conservative approach including brachytherapy, long-term penile integrity was maintained in 49 (68%).

CONCLUSION

Corpus involvement and clinically palpable nodes are highly statistically significant independent factors influencing overall survival. Node relapses remain a major cause of death. Thus, better management of lymph nodes is essential for improving survival even when conservative therapy is used to treat the primary.