Temporal relationship between cancers of the lung and upper aerodigestive tract

We retrospectively reviewed the chart records at the Veterans GeneralHospital-Taipei for the period between January 1985 and December 1994 toexamine the temporal relationship between cancers of the lung and upperaerodigestive tract. A total of 56 patients (54 males, 2 females) withhistocytologically proven double primary cancers, with either lung canceror upper aerodigestive tract cancers appearing first, were found. Squamouscell carcinoma was the most frequent histologic type of lung cancer(squamous 57%, adenocarcinoma 27%, poorly differentiated carcinoma 9%,small cell lung cancer 7%). The incidence of lung cancer patients withupper aerodigestive tract cancer was 0.9% (56/6412). There was nosignificant difference in the occurrence of upper aerodigestive tractcancer between non-small cell and small cell lung cancer (P > 0.05).However, the incidence of squamous cell lung cancer with upperaerodigestive tract cancer was higher than that of non-squamous cell lungcancer (P < 0.05). With regard to the location of lung cancer, the rightlung was more commonly affected than the left (P < 0.001). The locationsof upper aerodigestive tract cancers in these lung cancer patients were asfollows: larynx 24, nasopharynx 11, esophagus 10, hypopharynx 4, pharyngealtonsils 2, oral cavity 5. Most upper aerodigestive tract cancers werediagnosed before lung cancer (36/56, 64%), and lung cancer was diagnosedwithin 3 years in more than half of cases after the diagnosis of upperaerodigestive tract cancer (58.3%). Most lung cancers that preceded upperaerodigestive tract cancer were at an early stage at diagnosis (stage I 4,stage Illa 1), whereas the others, appearing either synchronously or afterthe diagnosis of upper aerodigestive tract cancer, were mostly at the latestage. There was no difference in survival between lung cancer patientswith upper aerodigestive tract cancer and those without (P > 0.05).