Japanese Lung Cancer Registry Study Research Articles

Epidemiology, risk factors and impact of cachexia on patient outcome: Results from the Japanese Lung Cancer Registry Study.

Cancer cachexia is a syndrome that does not fully recover with nutritional support and causes appetite loss and body weight loss. It worsens a patient's quality of life and prognosis. In this study, the epidemiology of cachexia in lung cancer, its risk factors and its impact on chemotherapy response rate and prognosis were examined using the national database of the Japan Lung Cancer Society. Understanding these things related to cancer cachexia is important as a starting point in overcoming cancer cachexia in patients with lung cancer. In 2012, 12320 patients from 314 institutions in Japan were registered in a nationwide registry database (Japanese Lung Cancer Registry Study). Of these, data on body weight loss within 6months were available for 8489 patients. We defined the patients with body weight loss≥5% within 6months, which is one of the three criteria listed in the 2011 international consensus definition of cancer cachexia, as cachectic in this study. Approximately 20.4% of the 8489 patients had cancer cachexia. Sex, age, smoking history, emphysema, performance status, superior vena cava syndrome, clinical stage, site of metastasis, histology, epidermal growth factor receptor (EGFR) mutation status, primary treatment method and serum albumin levels were significantly different between patients with and without cachexia. Logistic analyses showed that smoking history, emphysema, clinical stage, site of metastasis, histology, EGFR mutation, serum calcium and albumin levels were significantly associated with cancer cachexia. The response to initial therapy, including chemotherapy, chemoradiotherapy or radiotherapy, was significantly poorer in the patients with cachexia than in those without cachexia (response rate: 49.7% vs. 41.5%, P<0.001). Overall survival was significantly shorter in the patients with cachexia than in those without cachexia in both univariate and multivariable analyses (1-year survival rate: 60.7% vs. 37.6%, Cox proportional hazards model, hazard ratio: 1.369, 95% confidence interval: 1.274-1.470, P<0.001). Cancer cachexia was seen in approximately one fifth of the lung cancer patients and was related to some baseline patient characteristics. It was also associated with a poor response to initial treatment, resulting in poor prognosis. The results of our study may be useful for early identification and intervention in patients with cachexia, which may improve their response to treatment and their prognosis.

Impact of the preoperative body mass index on the postoperative outcomes in patients with completely resected non-small cell lung cancer: A retrospective analysis of 16,503 cases in a Japanese Lung Cancer Registry Study

ObjectivesThe aim of this study was to evaluate the impact of the preoperative body mass index (BMI) on the postoperative outcomes in patients with completely resected non-small cell lung cancer (NSCLC). Materials and methodsThe data of patients with NSCLC in whom R0 resection was achieved were extracted from the database of NSCLC samples accumulated by the Japanese Joint Committee of Lung Cancer Registry in the year 2010, and the surgical outcomes including postoperative morbidity, mortality and the prognosis, were evaluated. ResultsAmong 18,978 registered lung cancer cases, 16,509 patients (9996 men and 6513 women) were extracted. The median of age was 69 years old, and the histologic types included adenocarcinoma (n = 12,029), squamous cell carcinoma (n = 3286), large-cell carcinoma (n = 488) and others. The patients were divided into three groups according to their BMI: normal (BMI 18.5 to <25), underweight (BMI < 18.5) and overweight (BMI ≥ 25). Multivariate logistic regression analyses of factors associated with postoperative morbidity and mortality showed no significant differences among the three groups. In comparison to the normal group, the overall survival (OS) of the underweight group was significantly worse (p < 0.001) while that of the overweight group was marginally better (p = 0.075). A multivariate analysis of factors associated with OS showed that in addition to the age, sex and clinical stage, the preoperative BMI (underweight group vs. normal group: hazard ratio [HR] 1.417 [95% confidence interval {CI}: 1.278–1.572, p < 0.001], overweight group vs. normal group: HR 0.883 [95% CI: 0.806−0.967, p = 0.007]) was an independent prognostic factor. A multivariate analysis for the disease-free survival (DFS) also showed the preoperative BMI to be an independent significant prognostic factor. ConclusionsThe preoperative BMI is an independent prognostic factor in patients with completely resected NSCLC. A low preoperative BMI was associated with significantly poor survival in Japan.

A Japanese lung cancer registry study on demographics and treatment modalities in medically treated patients.

This study provides the benchmark statistics on medically treated patients with non–small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) in Japan. Demographic background, treatment, and prognosis were obtained from patients with lung cancer pathologically diagnosed in 2012, who received nonsurgical treatment. Descriptive statistics and their associations with survival were analyzed. In total, 12 320 patients were registered from 314 institutions in Japan. The median age was 70 years, and 73% of the patients were male. The number (%) of stages I, II, III, and IV diseases were 468 (3.8%), 421 (3.4%), 3260 (26.5%), and 8171 (66.3%), respectively. NSCLC and SCLC accounted for 9872 (80.1%) and 2353 (19.1%) patients, respectively. Thoracic radiotherapy‐based therapy, chemotherapy, and palliative care alone were administered to 2572 (20.9%), 7790 (63.2%), and 1952 (15.8%) patients, respectively. Clinical TNM stage was one of the strongest prognostic factors with the 3‐year survival rates of 62.9%, 47.3%, 40.0%, 27.8%, 37.5%, 26.5%, and 18.2% for stages IA, IB, IIA, IIB, IIIA, IIIB, and IV, respectively. Among 6158 patients with NSCLC treated with chemotherapy, the 3‐year survival rate was 33.4% in patients receiving epidermal growth factor receptor‐tyrosine kinase inhibitors (EGFR‐TKIs) at some point in their clinical course, whereas it was 17.4% in patients who did not. The 3‐year survival rate of SCLC was only 15.9%. In conclusion, approximately two‐thirds of the patients were diagnosed as stage IV at the initial diagnosis. Use of EGFR‐TKIs significantly improved the survival of patients with NSCLC.

ES 10.04 Carbon-ion Therapy

ES 10.04 Carbon-ion Therapy

SC03.03 Carbon-Ion Therapy of Lung Cancer

SC03.03 Carbon-Ion Therapy of Lung Cancer

Lobe-Specific Nodal Dissection for Clinical Stage I and II NSCLC: Japanese Multi-Institutional Retrospective Study Using a Propensity Score Analysis

ObjectivesThe purpose of this study was to assess the surgical outcomes according to the extent of mediastinal lymph node dissection for patients with NSCLC by using a nationwide registry database. MethodsFrom among 11,663 patients in a Japanese lung cancer registry study for 2004, 5392 patients with clinical stage (c-stage) I or II NSCLC that was completely resected by lobectomy and either systematic (SND) or lobe-specific nodal dissection (LSD) were enrolled. Patients who received preoperative therapy or had middle lobe tumor were excluded. In the LSD group, inferior mediastinal (subcarinal) nodes were not dissected for upper lobe tumors, and superior mediastinal nodes were not dissected for lower lobe tumors. To reduce the selection bias, an inverse probability of treatment weighting method using a propensity score was implemented. ResultsLSD and SND were performed in 1268 patients (23.5%) and 4124 patients (76.5%), respectively. The LSD group included more upper lobe and c-stage I tumors and less pathological N2 disease than the SND group. Extended pathological N2 disease outside LSD area was found in 3.2% of the SND group. The 5-year overall survival was 81.5% in the LSD group and 75.9% in the SND group. An inverse probability of treatment weighting–adjusted Cox model showed that LSD did not have a negative prognostic impact and instead was associated with favorable survival (hazard ratio = 0.68, 95% confidence interval: 0.60−0.77). ConclusionsThis retrospective registry study suggested that LSD is an alternative to SND for selected patients with c-stage I or II NSCLC. Future prospective studies are warranted to determine whether LSD is applicable and provides clinical benefit for the general population of patients with c-stage I or II NSCLC.

Clinicopathological characteristics and surgical results of lung cancer patients aged up to 50 years: The Japanese Lung Cancer Registry Study 2004

ObjectiveThe clinicopathological characteristics and surgical results of young lung cancer patients were investigated. Materials and methodsSeven hundred and four (6.0%) patients with lung cancer, aged up to 50 years, were enrolled from among the 11,663 patients registered in the Japanese Lung Cancer Registry Study 2004, and their clinical data were compared with those of 10,959 patients older than 50 years. This epidemiological study is based on the single year registration of surgically treated patients in the major institutes in Japan. ResultsThe 5-year overall survival rate (5Y-OS) and the 5-year lung cancer-related survival rate was 79.2%/69.0% (p<0.001) and 81.3%/76.6% (p=0.005) in the young/old groups, respectively. In the young/old groups, lobectomy and pneumonectomy was performed in 76.9%/78.0% and 5.7%/3.2%, respectively; adjuvant therapies were given preoperatively in 10.4%/4.7% (p<0.001) and postoperatively in 31.4%/24.5% (p<0.001). The proportions of patients with p-stage IIIA (18.2%) and adenocarcinoma histology (78.7%) were higher in the young group. The 5Y-OS was 94.8%/86.2% for p-stage IA (p<0.001), 87.0%/73.2% for p-stage IB (p=0.001), 61.0%/61.6% for p-stage IIA (p=0.595), 71.0%/48.4% for p-stage IIB (p=0.003), 49.6%/39.4% for p-stage IIIA (p=0.020), and 80.0%/24.8% for p-stage IIIB (p=0.012); it was 83.5%/80.7% for females (p=0.106) and 75.1%/62.3% for males (p<0.001) in the young/old groups. The postoperative survival was significantly better with all operative procedures in the young group. The 5Y-OS after recurrence was 17.9%/13.4% in the young/old groups (p=0.016). In the young group, the 5Y-OS was better in females (83.5%) than in males (75.1%, p=0.002), and for patients with adenocarcinoma (80.3%) than for those with squamous cell carcinoma (68.5%, p=0.013). Age up to 50 years was identified as an independent better prognostic factor on multivariate analysis. ConclusionsThe postoperative survival in lung cancer patients aged up to 50 years was better than that in patients older than 50 years.

Results of T4 Surgical Cases in the Japanese Lung Cancer Registry Study: Should Mediastinal Fat Tissue Invasion Really be Included in the T4 Category?

T4 lung cancer is a heterogeneous group of locally advanced disease. We hypothesized that patients in whom T4 lung cancer invaded only mediastinal fat tissue would show better prognosis after surgery than patients in whom T4 disease invaded other organs. The present study aimed to investigate how different invasive features of T4 disease impacted prognosis, and what types of patients with T4 disease could benefit most from surgical treatment. A nationwide registry study on lung cancer surgical cases during 2004 was conducted by the Japanese Joint Committee of Lung Cancer Registry, including registries of 11,663 cases within Japan. The present study analyzed 215 of these cases involving T4 structures or with ipsilateral nonprimary lobe pulmonary metastasis (PM). Reasons for T4 classification included invasion of only mediastinal tissue in 32 cases (15%), invasion of other structures in 96 cases (45%), and ipsilateral different lobe PM in 87 cases (40%); among these three groups, there were no significant differences in survival, nodal status, and patterns of first recurrence. Multivariate analysis showed an age of 70 years or above (p = 0.022) and nodal status (p = 0.004) to be significant prognostic factors. T4N0 patients less than 70 years of age showed significantly better prognosis than those who were T4N1-2 and 70 years of age or older (p = 0.0001; 5-year survival rate 50.3 versus 19.9%). There was no significant difference in survival between T4 patients with only mediastinal fat invasion and those with other T4 organ invasion and ipsilateral different lobe PM, demonstrating appropriateness of the T4 category definition in the current tumor, node, metastasis staging system. Age and nodal status were significant independent prognostic factors in T4 patients, and the best surgical candidates were shown to be T4N0 patients who were less than 70 years of age and had a 5-year survival rate of more than 50%.

Modern surgical results of lung cancer involving neighboring structures: A retrospective analysis of 531 pT3 cases in a Japanese Lung Cancer Registry Study

The aim of the present study was to identify the modern surgical results of pathologic T3 lung cancer and to examine the heterogeneity of this group from the nationwide database. The registered data of 11,663 cases from the Japanese Joint Committee of Lung Cancer Registry conducted in 2010 were analyzed, which included patients with resected lung cancer during 2004. Of these patients, 531 with invasive T3 lung cancer constituted the study population. Of the 531 patients, 466 were men and 65 women, with a mean age of 65.9 years. The 3- and 5-year survival rates and median survival time was 54.0%, 44.9%, and 46 months, respectively. A multivariate analysis showed incomplete resection, N2 disease, and no adjuvant therapy were independent prognostic factors of a poor outcome. However, pneumonectomy and N1 disease were not significantly associated with the prognosis. In terms of each involved structure, we detected 407 patients with T3 tumors involving the chest wall, 56 involving the mediastinal pleura, 45 with involvement of the bronchus within 2 cm of the carina, 31 involving the diaphragm, and 20 involving the pericardium. The corresponding 5-year survival rates were 43.2%, 40.1%, 55.2%, 42.6%, and 54.2%. The modern 5-year survival rates of patients with T3 lung cancer involving any neighboring structures have been 40% to 55%, and the current pT3 group was proved to have a relatively uniform prognosis.

Surgical Outcome of Stage IIIA- cN2/pN2 Non–Small-Cell Lung Cancer Patients in Japanese Lung Cancer Registry Study in 2004

The role of surgery in the treatment of non-small-cell lung cancer (NSCLC) with clinically manifested mediastinal node metastasis is controversial even in resectable cases because it is often accompanied by systemic micrometastasis. However, surgery is occasionally indicated for cases with single-station N2 disease or within multimodal treatment regimens, and in clinical trials. The aim of this study is to evaluate surgical outcomes in a modern cohort of patients with clinical (c-) stage IIIA-N2 NSCLC whose nodal metastasis was confirmed by pathology (cN2/pN2). From the central database of lung cancer patients undergoing surgery in 2004, which was founded by the Japanese Joint Committee for Lung Cancer Registration, data of patients having all conditions of NSCLC, c-stage IIIA, cN2, and pN2 were extracted, and the clinicopathologic profile of patients and surgical outcomes were evaluated. Among 11,663 registered NSCLC cases, 436 patients (3.8%) (332 men and 104 women) had been extracted. Their mean age was 65 years, and histologic types included adenocarcinoma (n = 246), squamous cell carcinoma (n = 132), and others (n = 58). The proportion of R0 resection was 82.5% and the proportion of the hospital deaths among the cause of death was 2.3%. The 5-year survival rate was 30.1% for the selected group of patients. The postoperative prognosis was significantly better than those of corresponding populations extracted from the 1994 (p = 0.0001) and 1999 databases (p = 0.0411). Men and women experienced a significantly different survival outcome (p = 0.025) with 5-year survivals of 27.5% and 37.8%, respectively. Single-station N2 cases occupied 60.9 % of the cohort and showed a significantly better prognosis than multistation N2 (p = 0.0053, 35.8 % versus 22.0 % survival rate at 5 years). The surgical outcomes of c-stage IIIA-cN2/pN2 NSCLC patients in 2004 were favorable in comparison with those ever reported.

Japanese Lung Cancer Registry Study of 11,663 Surgical Cases in 2004: Demographic and Prognosis Changes Over Decade

The Japan Lung Cancer Society, the Japanese Association for Chest Surgery, and the Japanese Respiratory Society jointly established the Japanese Joint Committee for Lung Cancer Registration, which has regularly conducted lung cancer registries for surgical cases in 5-year periods. We analyzed data obtained in these registries to reveal the most recent surgical outcomes and trends related to lung cancer surgery in Japan. Using data from the registry in 2010 for cases of surgery performed in 2004, demographics, surgical results, and stage-specific prognoses were analyzed. In addition, trends for those parameters over 10 years were assessed. The 5-year survival rate for all cases (n = 11,663, 7369 males, mean age 66.7 years) was 69.6%. The 5-year survival rates by c-stage and p-stage were as follow: IA, 82.0% (n = 6295) and 86.8% (n = 4978); IB, 66.8% (n = 2339) and 73.9% (n = 2552); IIA, 54.5% (n = 819) and 61.6% (n = 941); IIB, 46.4% (n = 648) and 49.8% (n = 848); IIIA, 42.8% (n = 1216) and 40.9% (n = 1804); IIIB, 40.3% (n = 90) and 27.8% (n = 106); and IV, 31.4% (n = 256) and 27.9% (n = 434), respectively. The percentages of female patients, cases with adenocarcinoma, stage I or II disease, and tumors sized less than 2 cm were increased, while those of operative and hospital deaths were decreased. Furthermore, the prognoses of all cases and cases in each stage improved over the decade. In Japanese cases of lung cancer surgery, demographics, surgical results, and stage-specific prognoses changed over the 10-year study period, while the 5-year survival rate for surgical cases improved to 69.6% in 2004.

Survival Differences by Gender for Resected Non-small Cell Lung Cancer: A Retrospective Analysis of 12,509 Cases in a Japanese Lung Cancer Registry Study

Women with non-small cell lung cancer (NSCLC) are more likely to have better survival than men. This study intended to assess gender differences in the survival of these patients in a large registry population. In 2005, the Japanese Joint Committee for Lung Cancer Registration performed a nationwide retrospective registry study regarding the prognosis and clinicopathologic profiles of patients who underwent resection for primary lung neoplasms in 1999. The registry data of 12,509 patients with NSCLC were analyzed in terms of gender differences in prognosis and clinicopathologic features. There were 8353 (66.8%) men and 4156 (33.2%) women with a mean age at operation of 66.4 and 65.0 years, respectively (p < 0.001). Women had a higher incidence of adenocarcinoma (p < 0.001) and stage IA disease (p < 0.001) than men. The overall survival was significantly better in women than men. The 5-year survival rates (5-YSRs) for women and men were 75.6 and 57.9%, respectively (p = 0.0000). According to histology, the overall survival of women was significantly better than that of men for both adenocarcinoma (5-YSR, 77.7 versus 61.9%, p = 0.0000) and nonadenocarcinoma (5-YSR, 59.3 versus 53.1%, p = 0.035). In adenocarcinoma, women had a significantly better prognosis than men for pathologic stage I/II disease. However, in nonadenocarcinoma, there was no significant prognostic difference between the two genders in pathologic stage I/II disease. Women with NSCLC, especially with an adenocarcinoma histology, had better survival than men. Women were more likely to have adenocarcinoma and stage IA disease, which might account for the better prognosis in women.

Japanese Lung Cancer Registry Study: First Prospective Enrollment of a Large Number of Surgical and Nonsurgical Cases in 2002

To investigate prognoses of lung cancer patients prospectively enrolled in the Japan Lung Cancer Registry Study. Patients newly diagnosed as having lung cancer exclusively in 2002 were enrolled. Follow-up surveys were performed twice, in 2004 and 2009, and the final follow-up data with prognoses were analyzed for 14,695 patients (79%). Clinical stages were defined according to the sixth edition of the International Union Against Cancer--tumor, node, metastasis classification (2002). The mean age was 67.1 years (range, 18-89 years), and there were 10,194 men (69.3%) and 4315 women (29.7%). The most frequent histology was adenocarcinoma (n = 8325, 56.7%), followed by squamous cell carcinoma (n = 3778, 26%) and small cell carcinoma (n = 1345, 9.2%). The distribution of clinical stages was as follows: IA, 4245 cases (29.3%); IB, 2248 (14.5%); IIA, 208 (1.4%); IIB, 918 (6.3%); IIIA, 1700 (11.8%); IIIB, 2110 (16.3%); and IV, 3037 (21.0%). The 5-year survival rates were 44.3% for all patients, 46.8% for those with non-small cell lung cancer, and 14.7% for those with small cell lung cancer. According to the clinical stage of non-small cell lung cancer and small cell lung cancer, the 5-year survival rates were 79.4 and 52.7% for stage IA, 56.9 and 39.3% for IB, 49.0 and 31.7% for IIA, 42.3 and 29.9% for IIB, 30.9 and 17.2% for IIIA, 16.7 and 12.4% for IIIB, and 5.8 and 3.8% for IV, respectively. Analysis of a large cohort in the Japanese registry study found that stage-specific prognosis was within a range similar to other reports. The data presented should provide an important reference for future clinical trials in Japan.

A Japanese Lung Cancer Registry Study at 2002

目的．本邦における2002年の肺癌治療成績を明らかにする．方法．肺癌登録合同委員会は，初診が2002年であった原発性肺癌を対象として登録を行い，2004年，2009年に追跡した．358施設から18,552例の登録がなされたが，生存期間の判明した14,695例を検討した．結果．男女比は2：1，平均年齢は67.1歳，分布は，組織型は腺癌が56.7%，扁平上皮癌が25.7%，小細胞癌が9.2%，臨床病期はIA期29.3%，IB期15.3%，IIA期1.4%，IIB期6.2%，IIIA期11.6%，IIIB期14.4%，IV期20.7%，手術あり症例は57.5%，手術なし症例は39.0%であった．5年生存率は，全組織型で44.3%，小細胞癌で14.7%，非小細胞癌で46.8%，手術あり症例，手術なし症例で，それぞれ66.0%，8.5%，男性，女性でそれぞれ37.7%，59.0%であった．臨床病期別では小細胞癌，非小細胞癌それぞれ，IA期（52.7%，79.4%），IB期（39.3%，56.9%），IIA期（31.7%，49.0%），IIB期（29.9%，42.3%），IIIA期（17.2%，30.9%），IIIB期（12.4%，16.7%），IV期（3.8%，5.8%）であった．結論．2002年の本邦における肺癌治療例は，腺癌が最も多く扁平上皮癌，小細胞癌が続いた．予後は5年の経過で，女性が男性より良く，非小細胞癌が小細胞癌より良く，手術あり症例が手術なし症例より良好であった．これらの差が生じている要因についてはさらなる検討を要する．

A Japanese Lung Cancer Registry Study: Prognosis of 13,010 Resected Lung Cancers

The validation of tumor, node, metastasis staging system in terms of prognosis is an indispensable part of establishing a better staging system in lung cancer. In 2005, 387 Japanese institutions submitted information regarding the prognosis and clinicopathologic profiles of patients who underwent pulmonary resections for primary lung neoplasms in 1999 to the Japanese Joint Committee of Lung Cancer Registry. The data of 13,010 patients with only lung carcinoma histology (97.6%) were analyzed in terms of prognosis and clinicopathologic characteristics. The 5-year survival rate of the entire group was 61.4%. For the small cell histology (n = 390), the 5-year survival rates according to clinical (c) and pathologic (p) stages were as follows: 58.8% (n = 161) and 58.3% (n = 127) for IA, 58.0% (n = 77) and 60.2% (n = 79) for IB, 47.1% (n = 17) and 40.6% (n = 29) for IIA, 25.3% (n = 38) and 41.1% (n = 29) for IIB, 29.0% (n = 61) and 28.3% (n = 60) for IIIA, 36.3% (n = 19) and 34.6% (n = 40) for IIIB, and 27.8% (n = 12) and 30.8% for IV (n = 13). For the non-small cell histology (n = 12,620), the 5-year survival rates according to c-stage and p-stage were as follows: 77.3% (n = 5642) and 83.9% (n = 4772) for IA, 59.8% (n = 3081) and 66.3% (n = 2629) for IB, 54.1% (n = 205) and 61.0% (n = 361) for IIA, 43.9% (n = 1227) and 47.4% (n = 1330) for IIB, 38.3% (n = 1628) and 32.8% (n = 1862) for IIIA, 32.6% (n = 526) and 29.6% (n = 1108) for IIIB, and 26.5% (n = 198) and 23.1% (n = 375) for IV. Adenocarcinoma, female gender, and age less than 50 years were significant favorable prognostic factors. This large registry study provides benchmark prognostic statistics for lung cancer. The prognostic difference between stages IB and IIA was small despite different stages. Otherwise, the present tumor, node, metastasis staging system well characterizes the stage-specific prognoses.

Prognosis of 6644 resected non-small cell lung cancers in Japan: A Japanese lung cancer registry study

Prognosis of 6644 resected non-small cell lung cancers in Japan: A Japanese lung cancer registry study

How should the TNM staging system for lung cancer be revised? A simulation based on the Japanese Lung Cancer Registry populations

The 1997 version of the TNM staging system for lung cancer has several prognostic problems. Among these, the overlapping survival of stages IB and IIA is the most serious. We performed this retrospective study to test a revised TNM staging system for lung cancer. We revised the T1 descriptor definition and stage grouping for testing as follows. According to the greatest tumor diameter, T1 tumors were divided into T1a tumors (< or =2.0 cm) and T1b tumors (2.1-3.0 cm). With these descriptors, new IA, IB, and IIA stages were defined as T1a N0 M0, T1b N0 M0, and T2 N0 M0 + T1 N1 M0, respectively. For 6644 patients with histologically non-small cell lung cancers resected in 1994 and reported in the Japanese Lung Cancer Registry Study, the survivals and prognostic difference between neighboring stages were studied. The 5-year survival of the entire population was 52.6%. In the clinical setting, the 5-year survivals of the new IA, new IB, new IIA, IIB, IIIA, IIIB, and IV stages were 77.5%, 69.3%, 49.8%, 40.6%, 35.8%, 28.0%, and 20.8%, respectively. In the pathologic setting, they were 83.7%, 76.0%, 60.0%, 42.2%, 29.8%, 19.3%, and 20.0%, respectively. For both clinical and pathologic settings, differences between all neighboring stages were statistically significant, except for that between IIIB and IV. Subcategorization of T1 and minor changes in stage grouping results in a system with significant differences in prognosis between neighboring stages. The unification of stages IB and IIA, especially, improves the discriminatory power of the staging system.

Prognosis of 6644 resected non-small cell lung cancers in Japan: A Japanese lung cancer registry study

For the scheduled future revision of the TNM staging system for lung cancer, it is important that the present 1997 version be evaluated in a large population. In 2001, the Japanese Joint Committee of Lung Cancer Registry sent a questionnaire to 320 Japanese institutions regarding the prognosis and clinicopathological profiles of patients who underwent the resection for primary lung neoplasms in 1994. We compiled the data for 7408 patients from 303 institutions (94.7%). Among these, 6644 patients with non-small cell histology were studied in terms of prognosis. The 5-year survival rate of the entire group was 52.6%. The 5-year survival rates by clinical (c-) stage were as follows: 72.1% for IA (n = 2423), 49.9% for IB (n = 1542), 48.7% for IIA (n = 150), 40.6% for IIB (n = 746), 35.8% for IIIA (n = 1270), 28.0% for IIIB (n = 366) and 20.8% for IV (n = 147). The difference in prognosis between neighboring stages was significant except for between IB and IIA and between IIIB and IV. The 5-year survival rates by pathological (p-) stage were as follows: 79.5% for IA (n = 2009), 60.1% for IB (n = 1418), 59.9% for IIA (n = 232), 42.2% for IIB (n = 757), 29.8% for IIIA (n = 1250), 19.3% for IIIB (n = 719) and 20.0% for IV (n = 259). The difference in prognosis between neighboring stages was significant except for between IB and IIA and between IIIB and IV. The survival curves of stages IB and IIA were almost superimposed in both c- and p-settings. These findings indicated that the present stages IB and IIA should be merged into the same stage category. Otherwise, the present TNM staging system seemed to well characterize the stage-specific prognosis in non-small cell lung cancer. The future revision should focus on the subdivision of stages I and II.