Lesions in patients with multifocal adenocarcinoma are more frequently in the right upper lobes.
OBJECTIVE
Opportunities to treat multifocal lung cancers, mostly adenocarcinoma, are increasing due to the development of imaging technologies. The optimal therapy modality to treat multifocally growing lung cancers remains obscure. To determine the features of multifocal lung cancers, we retrospectively reviewed patients with multiple lung lesions.


METHODS
Clinical, pathological and genetic characteristics of 31 patients with multifocal lesions were compared with those of patients who had had radical lung resection for solitary lung cancer. Gene mutation analyses for EGFR, KRAS and P53 were performed on three tumours of each of the patients who had four or more lesions.


RESULTS
Of the 31 patients, 17 had double tumours, 4 had triple tumours and 10 had 4 or more lesions. Patients with four or more lesions were significantly more likely to be females and never smokers. All of the histologically confirmed tumours of the cases with four or more lesions were adenocarcinoma in situ or lepidic predominant adenocarcinoma. The number of lesions in the right upper lobes when compared with the right lower lobes was significantly higher in patients with four or more lesions than in patients with double or triple lesions (P = 0.013). Five of the 12 tumours were positive for the EGFR mutation L858R in exon 21. No KRAS mutation was found.


CONCLUSIONS
Lesions in patients with multifocal adenocarcinoma are more frequently in the right upper lobes. Genetic analysis suggested that the specific EGFR mutation L858R in exon 21 might be the main factor contributing to lung carcinogenesis in multiple lung cancers. Further investigation of the right upper lobe in those patients compared with the lower lobes might provide more insights into lung carcinogenesis.
Division of Thoracic Surgery, Kansai Medical University Hirakata Hospital, Osaka, Japan. kanedah@hirakata.kmu.ac.jp
Hiroyuki
H
Kaneda
Yoshiko
Y
Uemura
Takahito
T
Nakano
Yohei
Y
Taniguchi
Tomohito
T
Saito
Toshifumi
T
Konobu
Yukihito
Y
Saito
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000368:Aged; D016009:Chi-Square Distribution; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009378:Neoplasms, Multiple Primary / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology*; D010641:Phenotype; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D014057:Tomography, X-Ray Computed; D016159:Tumor Suppressor Protein p53 / Q000235:genetics; D018631:ras Proteins / Q000235:genetics
C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C512478:EGFR protein, human; D066246:ErbB Receptors; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins