Cervical metastases from unknown primaries: radiotherapeutic management and appearance of subsequent primaries.

Between 1964 and 1986, 72 patients who presented with squamous or undifferentiated metastatic carcinoma to neck nodes, where the primary tumor could not be found by standard clinical procedures, were treated at the Mallinckrodt Institute of Radiology. These cases were managed in the following manner: biopsy and radiotherapy in 46 out of 72 patients, radiotherapy (RT) and a planned neck dissection in 14 out of 72, and neck dissection after failure to achieve a complete response (CR) with RT in 12 out of 72. Minimum follow-up was 2 years. The initial CR rates for stages N1, N2a, N2b, N3a, and N3b were 83%, 93%, 61%, 50%, and 33%, respectively. The long-term neck tumor control for the same stages was 83%, 71%, 67%, 44%, and 50%, respectively. One patient had soft tissue necrosis and two had carotid artery ruptures, one of which left no symptomatic sequelae. Twenty-one out of 72 patients developed subsequent primary tumor. Only one of these patients survived. This incidence was not affected significantly by prophylactic treatment of the mucosal areas except in patients with bilateral neck nodes, undifferentiated or poorly differentiated histologies, and/or posterior cervical node involvement. A multivariate analysis showed that prognosticators of an improved disease-free survival were: a complete clearance of tumor by the end of radiotherapy (p less than 0.0009) and no appearance of a subsequent primary tumor (p = 0.035). The only factor that correlated with an increased loco-regional control was having a complete response by the end of radiotherapy (p less than 0.00009). The recommended management and possible ways of preventing the appearance of subsequent primaries will be discussed.

The need for elective irradiation of occult lymphatic metastases from cancers of the larynx and pyriform sinus.

The incidence of palpable and occult cancer and the absence of cancer in lymph nodes were determined for individual sites in the larynx and pharynx of 540 patients who underwent neck dissection. The incidence of palpable cancer in lymph nodes was lowest for cancers of the central supraglottis and transglottis (32-41%), intermediate for cancers of the marginal supraglottis and glossoepiglottis (48-57%), and highest for cancers of the pyriform sinus (69%). The incidence of occult cancer in lymph nodes for individual sites in the larynx and pharynx was determined by pathologic study of neck dissection specimens from 253 patients without palpable lymph nodes (NO neck). The incidence of occult lymphatic metastases in the NO neck and the need for elective neck irradiation were least for cancers of the transglottis and central supraglottis (14-16%), intermediate for cancers of the glossoepiglottis and the marginal supraglottis (20-38%), and greatest for cancers of the pyriform sinus (47%). The risk of nodal recurrence increased from 8% for those without cancer in lymph nodes to 38% for those with occult or palpable cancer in lymph nodes. A policy of observing the NO neck in patients with a low incidence of occult lymphatic metastases and a low risk of neck recurrence to avoid the unnecessary irradiation of many to benefit a few is discussed.