|Year : 2010 | Volume
| Issue : 3 | Page : 468-469
Shortcomings of current TNM classification of carcinoma penis
Dharamveer Singh, Pawan Vasudeva, Satyanarayan Sankhwar
Department of Urology, C.S.M.M.U (Upgraded King George's Medical College), Lucknow, Uttar Pradesh, India
|Date of Web Publication||1-Oct-2010|
Department of Urology, C.S.M.M.U (Upgraded King George's Medical College), Lucknow, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Singh D, Vasudeva P, Sankhwar S. Shortcomings of current TNM classification of carcinoma penis. Indian J Urol 2010;26:468-9
Leijte JA, Gallee M, Antonini N, Horenblas S. Evaluation of current TNM classification of penile carcinoma. J Urol. 2008;180:933-8
| Summary|| |
The authors in this study have assessed the prognostic value of the currently followed TNM classification of carcinoma penis, which has remained unchanged since 1987.
From 1956 to January 2006, 513 patients with biopsy-proven penile squamous cell carcinoma for whom a follow-up of at least 3 months was available and none of them had received neoadjuvant chemotherapy were included in this retrospective study. All tumors were restaged according to the currently followed TNM classification. Most Tis, Ta, and T1 tumors had been treated with penile-sparing methods, those with T2 tumors <2 cm generally underwent penis conserving surgery, while those with larger T2 tumors had undergone partial penectomy. All T3/T4 tumors had been treated with partial/total penectomy. For a histologically proven tumor-positive groin, inguinal lymph node dissection had been done and if two or more positive inguinal lymph nodes were present, then ipsilateral pelvic lymph node dissection was also done. For extracapsular disease or tumor-positive pelvic lymph nodes, adjuvant radiotherapy was administered. For clinically node-negative disease, nodal status was not known for a number of patients with Tis, Ta, and T1 and even a minority with T2G1 and T2G2 prior to 1994 as nodal surgery had not been performed due to presumed low risk of positive nodes, that is, policy of watchful waiting had been employed. After 1994, node-negative patients with T1G3 or greater disease underwent sentinel node biopsy.
Median age at diagnosis was 65 years, median follow-up was 58.7 months, and 5-year disease-specific survival was 80.5%. Tumor grade and angioinvasion were significant predictors of survival (P < 0.001). No significant difference in survival was found between the pTis/Ta and pT1 categories (P = 0.063) as well as between the pT2 and pT3 groups (P = 0.568), while it differed significantly among all other pT categories. No significant difference in survival was found between the pN1 and pN2 groups (P = 0.176). Survival among the other pN categories differed significantly. The best prognostic stratification in the N category was realized by involving the laterality and fixity of inguinal lymph node involvement.
| Comments|| |
The TNM classification of malignant tumors is the most widely used tool for staging various malignancies. Since 1987, the TNM classification for penile carcinoma has remained unchanged and it has several shortcomings, so there is need to further improve its prognostic stratification and clinical usefulness.
Based on their analysis, the authors have proposed the following changes to the current TNM classification for penile cancer in an attempt to improve stage prognostication and facilitate clinical staging.
1. The authors have proposed that current T2 stage, that is, tumor involvement of the corpus-spongiosum and/or cavernosal bodies, be revised and be limited to tumors with corpus-spongiosum involvement. They propose that tumors with cavernosal involvement be staged as T3.
The authors have tried to emphasize upon the importance of corpus-cavernosum involvement in penile cancer. That such involvement increases risk of nodal metastasis and has a negative impact on survival has been documented in earlier studies. ,, The biological rationale for poorer prognosis may be that a tumor which is able to break through the relatively thick tunica-albuginea covering the cavernous bodies is likely to be an aggressive tumor.
2. Current T3 stage, that is, tumors with urethral/prostatic involvement be modified as mentioned earlier. Tumors involving the prostate should be downstaged to T4, which in the current TNM comprise of tumors directly invading into adjacent structures. This suggestion is based on the author's study finding that ingrowth into the prostate always occurred in combination with ingrowth in other adjacent structures. The authors propose that urethral involvement should not be taken into account while staging penile carcinoma.
3. Changes in nodal classification were also suggested based on:
- Accurate nodal staging is difficult because of the inability of clinical/imaging techniques to readily differentiate between superficial and deep inguinal nodes.
- The current nodal staging does not incorporate lymph node laterality, fixity/extracapsular nodal growth; however, the lymph node factors influencing survival adversely, for example, bilateral nodal metastases, number of positive inguinal nodes, pelvic nodal metastasis, and extranodal extension, have been reported in previous studies. ,
The authors have proposed N1 category as unilateral inguinal node involvement, N2 as bilateral inguinal node involvement, and N3 as pelvic lymph node involvement or a fixed inguinal node.
Although the suggestions are thought-provoking, whether these modifications can form the basis of a revised TNM classification is something that would need more studies for clarification.
| References|| |
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|3.||Slaton JW, Morgenstern N, Levy DA, Santos MW Jr, Tamboli P, Ro JY, et al. Tumor stage, vascular invasion and the percentage of poorly differentiated cancer: Independent prognosticators for inguinal lymph node metastasis in penile squamous cancer. J Urol 2001;165:1138-42. [PUBMED] |
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