Secondary malignancy among seminoma patients treated with adjuvant radiation therapy.

Abstract

PURPOSE:

Early-stage testicular seminoma is among the most radiosensitive tumors, with an overall cure rate of over 90%. Among those cured of the disease by orchiectomy and postoperative irradiation, there is a risk of having a second malignancy. We conducted a study to determine the relative risk of the occurrence of secondary malignancy.

METHODS AND MATERIALS:

From 1964 through 1988, 128 patients with histologically confirmed early-stage seminoma of the testis underwent orchiectomy and postoperative irradiation at the Radiation Oncology Center, Mallinckrodt Institute of Radiology, and affiliate hospitals. The follow-up periods ranged from 5 to 29 years, with a median of 11.7 years. The expected rate of developing a second cancer was computed by the standardized incidence ratio using the Connecticut Tumor Registry Database. The rate is based on the number of person-years at risk, taking into account age, gender, and race.

RESULTS:

Nine second nontesticular malignancies were found; the time of appearance in years is indicated in brackets: two squamous cell carcinomas of the lung [3, 11], one adenocarcinoma of the rectum [15], one chronic lymphocytic leukemia [2], one adenocarcinoma of the pancreas [14], one diffuse histiocytic lymphoma of the adrenal gland [7], one sarcoma of the pelvis [5], and two transitional cell carcinomas of the renal pelvis and ureter [14, 17]. One patient who developed a contralateral testicular tumor was excluded from risk assessment. The actuarial risk of second nontesticular cancer is 3%, 5%, and 20%, respectively, at 5, 10, and 15 years of follow-up. When compared with the general population, the overall risk of second nontesticular cancer in the study group did not reach the 0.05 significance level, with an observed/expected (O/E) ratio of 2.09 (95% confidence interval, 0.39-3.35). When analyzed by the latency period after radiation treatment, during the period of 11 to 15 years, the risk was higher (O/E ratio of 4.45, 95% confidence interval, 1.22-11.63) than expected. The median duration for developing a second cancer was 11 years for tumors arising from tissues outside the irradiated field and 14 years for those within or near the irradiated area.

CONCLUSIONS:

The overall observed incidence of second nontesticular malignancy among patients with early-stage testicular seminoma treated with adjuvant radiation therapy was not significantly increased in comparison with the expected incidence. Clinical implications are discussed.

• Authors: C K Chao, P P Lai, J M Michalski, C A Perez
• Journal: International journal of radiation oncology, biology, physics (Int J Radiat Oncol Biol Phys) Vol. 33 Issue 4 Pg. 831-5 (Nov 01 1995) ISSN: 0360-3016 [Print] United States
• PMID: 7591890 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Adolescent
• Adult
• Aged
• Combined Modality Therapy
• Follow-Up Studies
• Humans
• Incidence
• Male
• Middle Aged
• Neoplasms, Radiation-Induced (epidemiology)
• Neoplasms, Second Primary (epidemiology, etiology)
• Orchiectomy
• Retrospective Studies
• Seminoma (radiotherapy, surgery)
• Testicular Neoplasms (radiotherapy, surgery)