Tetsuro Kondo

Clinicopathological features and EGFR gene mutation status in elderly patients with resected non-small-cell lung cancer

BackgroundThe rapid aging of the population in Japan has been accompanied by an increased rate of surgery for lung cancer among elderly patients. It is thus an urgent priority to map out a treatment strategy for elderly patients with primary lung cancer. Although surgical resection remains standard treatment for early stage non–small-cell lung cancer (NSCLC), it is now essential to confirm the status of epidermal growth factor receptor (EGFR) gene mutations when planning treatment strategies. Furthermore, several studies have reported that EGFR mutations are an independent prognostic marker in NSCLC. However, the relations between age group and the molecular and pathological characteristics of NSCLC remain unclear. We studied the status of EGFR mutations in elderly patients with NSCLC and examined the relations of EGFR mutations to clinicopathological factors and outcomes according to age group.MethodsA total of 388 consecutive patients with NSCLC who underwent complete tumor resection in our hospital from 2006 through 2008 were studied retrospectively. Formalin-fixed, paraffin-embedded tissue sections were used to isolate DNA from carcinoma lesions. Mutational analyses of EGFR gene exons 19, 20, and 21 and KRAS gene exons 12 and 13 were performed by loop-hybrid mobility shift assay, a highly sensitive polymerase chain reaction-based method.ResultsEGFR mutations were detected in 185 (47.7%) and KRAS mutations were detected in 33 (8.5%) of the 388 patients. EGFR mutations were found in a significantly higher proportion of patients younger than 80xa0years (younger group; 178/359, 49.6%) than in patients 80xa0years or older (older group; 7/29, 24.1%) (Pu2009=u20090.008). In contrast, KRAS mutations were more common in the older group (6/29, 20.7%) than in the younger group (27/359, 7.5%) (Pu2009=u20090.014). The older group showed a trend toward a higher rate of 5-year overall survival among elderly patients with EGFR mutations (100%) than among those with wild-type EGFR (66.2%), but the difference was not significant.ConclusionsOur results suggest that the EGFR status of patients with NSCLC differs between patients 80xa0years or older and those younger than 80xa0years. EGFR mutation status might be a prognostic marker in elderly patients with completely resected NSCLC.

Growth rate of lung cancer recognized as small solid nodule on initial CT findings

INTRODUCTIONnTo study the characteristics of lung cancer, appearing as small solid nodules on initial computed tomography (CT) findings, and to determine an appropriate follow-up duration so as to differentiate between malignancy and benign tumor.nnnMETHODSnWe analyzed the records of 34 patients who had undergone surgical resection of lung cancer, which appeared as small solid nodules on initial CT findings. We studied the CT findings, volume doubling times (VDT), follow-up durations, pathological and clinical findings.nnnRESULTSnVDT is classified as follows: (1) slow growth group (SGG), with a VDT of more than 700 days and (2) rapid growth group (RGG), with a VDT of less than 700 days. The median VDT of the SGG was 1083 days, and the RGG was 256 days (p<0.01). The median duration for follow-up of the SGG was 1218 days, and 179 days for the RGG. A statistical difference was noted in the follow-up durations (p<0.01). There were no statistical differences in the preoperative thin-section CT (TSCT) findings, or in the pathological findings. The RGG included more patients with smoking histories. The CT findings of RGG tended to reveal changed in base lung field such as emphysema, and lung fibrosis.nnnCONCLUSIONSnGenerally, lung cancer appearing as small solid nodules on initial CT findings grew rapidly, but there were some cases which displayed slow growth patterns. These cases required follow up for over two years, before diagnosis was possible. We concluded the appropriate maximum followup duration is three years.

Recurrent EML4–ALK-associated lung adenocarcinoma with a slow clinical course

The fusion gene EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene) was recently identified as a novel genetic alteration in non-small-cell lung cancer. The clinicopathological features of EML4-ALK-positive adenocarcinoma are reported to include its high incidence in young, non-smoking patients, tumors that show distinct solid or acinar growth patterns with or without signet-ring cell histology, and its mutually exclusive occurrence with mutations in EGFR and KRAS. However, the clinical findings have not been well described. Here, we report a case of EML4-ALK-positive lung adenocarcinoma that showed multiple metachronous lesions on the pleura and pulmonary field, suspected to be a recurrence of lung adenocarcinoma after a 20-year disease-free interval. The slow clinical course may be characteristic of EML4-ALK-positive lung adenocarcinoma. Therefore, long-term observation of patients with EML4-ALK-positive lung adenocarcinomas is required after surgery.

Correlations of thin-section computed tomographic, histopathological, and clinical findings of adenocarcinoma with a bubblelike appearance.

Objective: We reported that adenocarcinomas with a bubblelike appearance (BLA) appear similar to old inflammation (J Comput Assist Tomogr 2009;33:42-48). The histopathological, clinical, and biological characteristics of adenocarcinomas with BLA need more investigation. Methods: We retrospectively reviewed the records of 26 patients who had undergone surgical resection between 1993 and 2008. We analyzed correlations between thin-section computed tomographic (TS-CT), histopathological, and clinical findings. We analyzed epidermal growth factor receptor and K-ras gene mutations. Results: The TS-CT findings are unique with one pattern that was the same in all the 26 cases: (1) polygonal with straight and concave margins, (2) slight peripheral ground-glass opacity areas, (3) 3 or more dilated air bronchograms, and (4) clear pleural indentations. The histopathological findings were identical with our TS-CT findings. The mean tumor doubling time was 1165 days. Epidermal growth factor receptor mutations were observed in 17 cases. There were no K-ras mutations. After resection, the 5-year survival rate is 100%. Conclusion: The adenocarcinomas with BLA have unique TS-CT, histopathological, and clinical findings.

Prognostic value of preoperative FDG-PET in stage IA lung adenocarcinoma

BACKGROUNDnMaximum standardized uptake value (SUVmax) of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) has been found to have prognostic value. We previously reported the correlation between SUVmax and pathological invasive area, and determined an SUVmax cut-off value of 2.15 for predicting the recurrence potential of an invasive area of diameter 5mm. Here, we evaluate the validity of FDG-PET for prediction of recurrence in pathological stage IA lung adenocarcinoma.nnnMETHODSnFrom February 2006 to May 2008, 100 patients with pathological stage IA lung adenocarcinoma underwent complete resection at our hospital. Tumors were classified as air-type or solid-type based on thin-section computed tomography (TS-CT) findings and the influence of TS-CT classification, SUVmax, and clinicopathologic features were evaluated in terms of the incidence of recurrence.nnnRESULTSnUnlike air-type adenocarcinomas, recurrent disease was detected in 8 of 62 solid-type adenocarcinomas. SUVmax and diameter of invasive area were significantly correlated with recurrence and a shorter time to recurrence. All 8 recurrent cases had pathological invasive area >5mm. All except one case of recurrence were solid-type adenocarcinomas with SUVmax≥2.15. Three-year disease-free survival rates were 100% in air-type adenocarcinomas, 97.1% in solid-type adenocarcinomas with SUVmax<2.15, and 74.1% in solid-type adenocarcinoma with SUVmax≥2.15.nnnCONCLUSIONnCombined evaluation of TS-CT classification and SUVmax had significant value in predicting recurrence in stage IA lung adenocarcinoma, reflecting the aggressiveness of primary lung adenocarcinoma. Prediction of tumor aggressiveness could contribute to decision-making regarding the choice of surgical procedure and treatment after surgery.