Late Development of Laryngeal Cancer in Previously Irradiated Larynx

Five cases of recurrent laryngeal cancer, occurring 5 or more years after having radiotherapy for the treatment early glottic cancer of the larynx, are reported.Case I received irradiation for glottis T1aN0 of the left vocal cord. Thirteen years later, a total laryngectomy was performed for cancer of the right vocal cord extending to the subglottis.Case II received irradiation for glottis T1aN0 of the right vocal cord. Thirteen years later, reradiation was performed for cancer of the right vocal cord and false cord. Ultimately, a total laryngectomy was required and performed three years after the re-radiation.Case III received irradiation for glottis T1aN0 of the left vocal cord. Nine years later, an emergency tracheotomy followed by a total laryngectomy was performed for a subglottic tumor.Case IV received irradiation for glottis T1aN0 of the left vocal cord. Five years and 4 months later, glottis T2N0 of the left vocal cord was detected. The patient expired of progressive prostate cancer.Case V received irradiation for anterior subglottis T1N0. Eight years later, a total laryngectomy was performed for glottis T3N0 of the left vocal cord.There are three possible causes for carcinogenesis for these cases : late recurrence (persistence of the original carcinoma), radiation induced cancer and multicentric cancerization. Long-term followup seems to be necessary even with early stage laryngeal cancer patients.