Multiple Primary Bronchial Carcinomas

Abstract

Multiple synchronous and metachronous primary lung tumors are being recognized with greater frequency than previously reported. When they are found as separate primary tumors, definitive resectional therapy is possible in some patients. The actual incidence of synchronous primary lung tumors is difficult to determine, but the risk of multiple metachronous primary lung tumors appears to increase with the selectivity of the patient population under consideration. When the entire population with carcinoma of the lung is observed, approximately 0.5% of the patients will have a second primary lung tumor diagnosed before death. When the population is limited to those patients who undergo resection, the risk increases to about 2% and when only long-term survivors are considered, it approaches 10%. Even though Salemo and associates (p 3, this issue) observed in their experience that most of the second primary lesions were discovered within two to four years after the initial resection, the data from the Veterans Administration Surgical Adjuvant Group indicate that most of these lesions are seen after the fifth year. Among 535 five-year survivors, a second primary lung tumor was noted in 41 patients. It was found in only 10 before the end of the fifth year and in 31 after the fifth year. In a later study of 257 patients who had survived ten years, 25 new lung tumors were identified; only 1 before the end of the fifth year and the other 24 after that date. In the patient population reviewed, new primary lung tumors continued to be identified as long as sixteen years after the initial operation. These data suggest that the development of such a lesion may be expected to be observed until the entire population under observation has died. Although it is difficult, i f not impossible in most instances, to rule out the second lesion as being metastasis from the first, the clinician