Ryosuke Tsuchiya

Screening for Lung Cancer With Low-Dose Helical Computed Tomography: Anti-Lung Cancer Association Project

PURPOSE Because efficacy of lung cancer screening using chest x-ray is controversial and insufficient, other screening modalities need to be developed. To provide data on screening performance of low-dose helical computed tomography (CT) scanning and its efficacy in terms of survival, a one-arm longitudinal screening project was conducted. PATIENTS AND METHODS A total of 1,611 asymptomatic patients aged 40 to 79 years, 86% with smoking history, were screened by low-dose helical CT scan, chest x-ray, and 3-day pooled sputum cytology with a 6-month interval. RESULTS At initial screening, the proportions of positive tests were 11.5%, 3.4%, and 0.8% with low-dose helical CT scan, chest x-ray, and sputum cytology, respectively. In 1,611 participants, 14 (0.87%) cases of lung cancer were detected, with 71% being stage IA disease and a mean tumor diameter of 19.8 mm. At repeated screening, the proportions of positive tests were 9.1%, 2.6%, and 0.7% with low-dose helical CT, chest x-ray, and sputum cytology, respectively. In 7,891 examinations, 22 (0.28%) cases of lung cancer were detected, with 82% being stage IA disease and a mean tumor diameter of 14.6 mm. The 5-year survival rate for screen-detected lung cancer was 76.2% and 64.9% for initial and repeated screening, respectively. CONCLUSION Screening with low-dose helical CT has potential to improve screening efficacy in terms of reducing lung cancer mortality. An evaluation of efficacy using appropriate methods is urgently required.

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

Purpose: 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. Methods: 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. Results: 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. Conclusion: 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.

The Importance of Surgery to Non-Small Cell Carcinoma of Lung with Mediastinal Lymph Node Metastasis

In the past 25 years, 1,654 patients with non-small cell cancer underwent resection at National Cancer Center Hospital, Tokyo. A comparative study has been made of 5-year survival of patients who had pulmonary resection with and without mediastinal lymph node dissection. There were 426 patients (25.8% of the total) with N2 M0 disease. Of these, 345 underwent pulmonary resection with mediastinal lymph node dissection. The 5-year survival in this group was 15.9% (T1 N2 M0, 30.0%; T2 N2 M0, 14.5%; and T3 N2 M0, 12.9%). In the remaining 81 patients, who did not have mediastinal lymph node dissection, 5-year survival was 6.7%. Of the 426 patients with N2 M0 disease, 242 were select patients who underwent a curative operation with an overall 5-year survival of 19.2%. Sixty-six of them had squamous cell carcinoma and a 5-year survival of 30.8%; 153 had adenocarcinoma and a survival of 16.0%; 14 had large cell carcinoma and a survival of 12.8%; and 9 had adenosquamous cell carcinoma, and none survived 5 years. To improve the end results, it is important to perform as many curative operations with mediastinal lymph node dissection as possible. Histological cell type and tumor status must be taken into consideration.

Prognosis and survival after resection for bronchogenic carcinoma based on the 1997 TNM-staging classification: the Japanese experience

BACKGROUND A new TNM staging system was proposed, and the previous system was revised in 1997. METHODS To evaluate the new TNM staging system for lung cancer, records of 3,043 lung cancer patients who underwent pulmonary resection at the National Cancer Center Hospital, Tokyo, were analyzed. RESULTS With regard to clinical stages, 3 patients had occult carcinoma; 786 patients had stage IA disease; 759 patients, stage IB; 54 patients, stage IIA; 469 patients, stage IIB; 582 patients, stage IIIA; 211 patients, stage IIIB; and 179 patients, stage IV. The 5-year survival rates for the respective stages were 70.8% for stage IA, 44.0% for stage IB, 41.1% for stage IIA, 36.9% for stage IIB, 22.7% for stage IIIA, 20.1% for stage IIIB, and 21.6% for stage IV. In terms of postoperative stages, 7 patients were classified in stage 0, 610 in stage IA, 506 in stage IB, 114 in stage IIA, 432 in stage IIB, 702 in stage IIIA, 448 in stage IIIB, and 224 in stage IV. The 5-year survival rates were as follows: stage IA, 79.0%; stage IB, 59.7%; stage IIA, 56.9%; stage IIB, 45.0%; stage IIIA, 23.6%; stage IIIB, 16.5%; and stage IV, 5.1%. CONCLUSIONS In the clinical stage, there were significant prognostic differences between stage IA and stage IB, stage IIB and IIIA, and stage IIIA and stage IIIB, but there was no significant difference in 5-year survival rates between stage IB and stage IIA, stage IIA, and IIB, and stage IIIB and stage IV. In the postoperative stage, there were significant differences in 5-year survival rates between each stage except for stage IB and stage IIA.

Pulmonary resection for metastatic colorectal cancer: Experiences with 159 patients ☆ ☆☆ ★ ★★

We reviewed the clinical courses of 159 patients between February 1967 and May 1995 for the purpose of examining the survival of patients who had pulmonary resection for metastatic colorectal cancer. The cumulative survivals at 5 years and 10 years were 40.5% and 27.7%, respectively. Fifteen patients (10%) were alive more than 10 years after the thoracotomy without any evidence of recurrence. The cumulative survival at 5 years for 39 patients who had hepatic metastases before thoracotomy was 33%. There was a statistically significant difference in survival between patients with extrapulmonary metastases and those with only intrapulmonary metastases before thoracotomy. The number of pulmonary metastases and the presence of hilar or mediastinal lymph node metastases affected postthoracotomy survival. There was no significant difference in survival on the basis of sex, age, location of the primary cancer, size of the pulmonary tumors, mode of operation, or disease-free interval. Surgical treatment for pulmonary metastases from colorectal cancer in selected patients, even those who had hepatic metastases before thoracotomy, might improve prognosis.

Lobe-specific extent of systematic lymph node dissection for non-small cell lung carcinomas according to a retrospective study of metastasis and prognosis.

BACKGROUND Complete lymphadenectomy of the mediastinum is advised for patients with lung cancer to provide prognostic information and possible survival benefit. The proper extent of dissection should be further defined. METHOD The lymphatic metastatic patterns according to the primary site and prognoses were retrospectively analyzed in 166 patients with non-small cell carcinoma who underwent at least lobectomy with hilar and mediastinal lymphadenectomy. All patients had histologically proven mediastinal metastasis (pN2). RESULTS Among 54 right upper lobe tumors the most common site of metastasis was the lower pretracheal station (74%), whereas metastases to the subcarinal station were seen only in 13%. Among 8 patients with right middle lobe tumors and 41 patients with right lower lobe tumors, both superior mediastinal and subcarinal stations were involved. The 34 left upper segment tumors metastasized to the aorticopulmonary window most commonly (71%) and to the subcarina only in 12% of cases. Inversely, the 10 left lingular tumors metastasized to the subcarina most commonly (50%) and to the aorticopulmonary window only in 20% of cases. Among 44 left lower lobe tumors the subcarinal station was most common for metastasis (58%), with infrequent metastases to the aorticopulmonary window. The 5-year survival for all 166 patients was 35%. Patients with single-station and single-node metastases had a significantly better prognosis than those with more extensive metastases. Right lower lobe tumors with superior mediastinal metastasis carried a particularly poor 5-year survival of only 4.1%. COMMENT Subcarinal lymphadenectomy is not always necessary for tumors of the right upper lobe and left upper segment. For tumors of other lobes both superior mediastinal dissection and subcarinal dissection are advised. However, superior mediastinal metastasis should be recognized as an indicator of poor prognosis in tumors of both lower lobes.

Thymoma: a clinicopathologic study based on the new World Health Organization classification

OBJECTIVE This study explored the relationship between the histologic subtype of thymoma according to the new World Health Organization histologic classification and the clinical findings, as well as the prognostic significance of the classification. METHODS A total of 130 patients with thymoma, who underwent resection at the National Cancer Center Hospital, Tokyo, from 1962 to 2000, were studied retrospectively. The histologic subtype of thymoma was determined according to the new World Health Organization histologic classification. The stage was also determined according to a modified Masaokas classification as stage I, II, III, IVa, or IVb. To determine the factors that may affect the prognosis of thymoma, a multivariate analysis with Coxs proportional hazards regression model was performed. RESULTS The distribution of histologic subtype was type A (n = 18), type AB (n = 56), type B1 (n = 15), type B2 (n = 29), and type B3 (n = 12). A close correlation was seen between the histologic subtype and stage (P =.000). The overall survivals at 5 and 10 years were 92% and 91%, respectively. The 5- and 10-year survivals according to stage were 100% and 100% (stage I, n = 40; stage II, n = 54), 81% and 76% (stage III, n = 25), and 47% and 47% (stage IV, n = 11), respectively. The difference in survival between stage III and stage IV was significant (P =.000). Patients with type A or AB thymoma demonstrated a 100% survival at both 5 and 10 years. Recurrences were seen in 12 patients with complete resection. According to a multivariate analysis, tumor size (P =.001), completeness of resection (P =.002), histologic subtype (P =.011), and stage (P =.00) were significant prognostic factors. CONCLUSION The World Health Organization histologic classification significantly correlated with the clinical stage. Tumor size, completeness of resection, histologic subtype, and stage predicted the prognosis of thymoma.

Grade of stromal invasion in small adenocarcinoma of the lung: histopathological minimal invasion and prognosis.

The pathologic features of invasion such as stromal disruption and pleural/vascular involvement have been shown to be of prognostic value in adenocarcinoma. However, the relationship between the degree of invasion, histologic subtype of adenocarcinoma, and prognosis remains unclear. We retrospectively studied 380 peripheral adenocarcinomas of ≤2.0 cm in diameter with regard to histology and clinical profiles. Their degree of invasive growth was classified into four grades as follows according to the structural deformity and its location in the adenocarcinoma lesion: Grade 0 had a pure bronchioloalveolar growth pattern and no evidence of stromal invasion. Grade 1 had stromal invasion in the area of bronchioloalveolar growth. Grade 2 had stromal invasion localized on the periphery of a fibrotic focus. Grade 3 had stromal invasion into the center of a fibrotic focus. The clinicopathological data were obtained from medical records. The distribution of the histologic grade of invasion was as follows: grade 0 in 85 tumors (22%), grade 1 in 37 (10%), grade 2 in 46 (12%), and grade 3 in 212 (56%). This histologic grade of invasion was closely related to other indicators of tumor spread. Vascular/lymphatic permeation was seen in none of grade 0, in 1 lesion each of grade 1 and grade 2, and 144 (68%) of grade 3. Lymph node metastasis was seen in 57 (27%) lesions of grade 3 but not in grades 0, 1, or 2. The 5-year disease-free survival rates were 100%, 100%, 100%, and 59.6% for tumors with grade 0, grade 1, grade 2, and grade 3 invasion, respectively. Tumors with grade 1 and grade 2 invasion, like tumors with grade 0 invasion (bronchioloalveolar carcinoma), showed an excellent prognosis. Therefore, tumors with grade 1 and grade 2 invasion could be considered “minimally invasive” or “early” adenocarcinomas.

Lymph node sampling in lung cancer: how should it be done?

OBJECTIVES Systematic lymph node dissection in radical operation for lung cancer is recognized as an operative procedure which is expected to improve local control. We investigate the most effective method of lymph node dissection or sampling. METHODS A retrospectrive study was carried out on 1815 patients who underwent systematic lymph node dissection and complete resection. The lymphatic route of metastatis from each lobe was investigated by examining which nodes had the most likelihood of metastasis, or to find out which is the sentinel lymph node in the case of small sized tumor, suitable for the video assisted thoracic surgery (VATS) approach. RESULTS At N2 level, distribution of major metastases from each lobe are as follows: right upper lobe tumor, #3 - 12.3% (80/648) and/or #4 - 8% (52/648); right middle lobe tumor, #3 and/or #7 - 16.4% (13/79); right lower lobe tumor, #7 - 13.7% (52/380); left upper lobe tumor, #5 - 12.3% (60/489) and/or #6 - 6.7% (33/489); and left lower lobe tumor, #7 - 11.9% (26/219). Small sized tumor requires lymph node sampling upon staging, and the lymph node most likely to become the first metastasis, i.e. sentinel node, are as follows: regardless of the location of tumor, #12, #11, and/or #10 in N1 level, which means dissection or sampling within these locations of lymph nodes are prerequisite. In N2 level, #3 and/or #4 in right upper lobe tumor, #3 and/or #7 in right middle lobe tumor, #7 in right lower lobe tumor, #5 and/or #6 in left upper lobe tumor, and, #7 in left lower lobe tumor. CONCLUSIONS In clinical T1NO lung cancer, sentinel lymph node sampling should be done first, if the nodes are negative, complete mediastinal lymph node dissection might be omitted. On the other hand, if the sentinel nodes are positive for pathology, complete medistinal lymph node dissection is required for curative resection.

Progression of focal pure ground-glass opacity detected by low-dose helical computed tomography screening for lung cancer.

Objective: To clarify the progression of focal pure ground-glass opacity (pGGO) detected by low-dose helical computed tomography (CT) screening for lung cancer. Methods: A total of 15,938 low-dose helical CT examinations were performed in 2052 participants in the screening project, and 1566 of them were judged to have yielded abnormal findings requiring further examination. Patients with peripheral nodules exhibiting pGGO at the time of the first thin-section CT examination and confirmed histologically by thin-section CT after follow-up of more than 6 months were enrolled in the current study. Progression was classified based on the follow-up thin-section CT findings. Results: The progression of the 8 cases was classified into 3 types: increasing size (n = 5: bronchioloalveolar carcinoma [BAC]), decreasing size and the appearance of a solid component (n = 2: BAC, n = 1; adenocarcinoma with mixed subtype [Ad], n = 1), and stable size and increasing density (n = 1: BAC). In addition, the decreasing size group was further divided into 2 subtypes: a rapid-decreasing type (Ad: n = 1) and a slow-decreasing type (BAC: n = 1). The mean period between the first thin-section CT and surgery was 18 months (range: 7–38 months). All but one of the follow-up cases of lung cancer were noninvasive whereas the remaining GGO with a solid component was minimally invasive. Conclusions: The pGGOs of lung cancer nodules do not only increase in size or density, but may also decrease rapidly or slowly with the appearance of solid components. Close follow-up until the appearance of a solid component may be a valid option for the management of pGGO.