Thoracic Surgery

Introduction
The Thoracic Surgery Division deals surgically with various kinds of neoplasms in the thorax: lung tumors both primary and metastatic, mediastinal, pleural (meso-theliomas), chest wall and esophageal tumors. The surgical treatment of pulmonary carcinoma with various surgical techniques has been the major challenge of the division. The modes of surgical treatment for carcinoma range from simple resection (lobectomy and pneumo-nectomy) to more complex approaches such as combined resection with neighboring structures, perioperative treatment and thoracoscopic surgery.
The Division includes four staff surgeons and 2-4 residents. One third or more of our three year residency program in general thoracic surgery is dedicated to the study of pathology, endoscopy, image diagnosis and medical oncology depending on each residentﾕs preference. This rotation system for related oncological specialties provides our residents with a better understanding of each field.
The number of patients who undergo surgical intervention in our division is one of the 3 largest in Japan, and we have been among the most active leaders in this field since the division was established 1992.

Routine Activities
All possible candidates for surgical intervention are presented at our conference with Thoracic Oncology Divison every Tuesday evening to determine the most appropriate treatment modalities. Selected patients among those who underwent resection are pathologically reviewed on every Friday morning.
Pulmonary carcinomas of non-small cell histology in clinical stages I, II and IIIA and of small cell histology in clinical stages I and II are usually indicated for curative surgical resection of the disease. On the other hand, to improve the poor prognosis of patients with mediastinal lymph node metastases proven clinically and histologically, those with disease invading neighboring vital structures, or who have small cell cancer, the optimal treatment modalities are sought for in clinical trial settings.
Resection of metastatic lung tumors has been attempted for those meeting Thomfoldﾕs criteria with slight modification upon consultation with the patient. Histologically, metastases from colorectal carcinomas comprise the majority of cases. The majority of mediastinal tumors were thymic epithelial tumors, and we did not attempt thoracoscopy in these patients.

Research Activities
Ongoing Clinical Trials
1. Surgery alone vs. preoperative chemotherapy followed by surgery for histologically proven cN2 non-small cell lung carcinoma [phase III].
2. No adjuvant treatment vs. postoperative adjuvant chemotherapy for resected non-small cell carcinoma with histologically proven mediastinal lymph node metastases [phase III].
3. No treatment vs. hypotonic cisplatin treatment for resected non-small cell lung carcinoma with positive pleural lavage cytology at the time of thoracotomy [phase III].

New Developments
Thoracoscopy is now routinely indicated for the resection of benign/undetermined mediastinal or pulmonary tumors, and exploration of the thoracic cavity for accurate staging of lung carcinoma. The difficulty in detecting small and/or deeply situated target nodules has been a major factor limiting the success of thoracoscopic resection. Very recently, we succeeded in marking such nodules with CT-fluoroscopy-guided injection of n-butyl-2-cyanoacrylate, which formed a hard nodule easily detectable thoracoscopically.
In order to reduce surgical invasiveness, especially in elderly and poor-risk patients, major or conservative pulmonary resection with thoracoscopic assistance is being attempted, but only in a small number of patients.

Statistics

Number of Patients treated in 1995-1997

1995 1996 1997

Lung carcinoma 155 188 176

Metastatic lung tumor 26 14 23

Mediastinal tumor 18 19 18

Others 46 21 38

Total 261 266 278

Operative Method for Primary Lung Carcinoma

1995 1996 1997

Lung resection 137 167 161

Pneumonectomy 4 7 9

Lobectomy 127 151 147

(Bronchoplasty) (8) (3) (4)

Conservative resection 6 9 5

Thoracoscopic resection
(including staging) 16 30 16

Others 13 10 15

Survival Rates for Resected Primary Lung Carcinoma
Stage 3-yr (%) 4-yr (%)

Stage I 87.8 80.8

Stage II 74.0 64.8

Stage IIIA 52.8 36.3

Stage IIIB 36.3 -

Stage IV 21.7 -

Number of Patients treated in 1995-1997
	1995	1996	1997
Lung carcinoma	155	188	176
Metastatic lung tumor	26	14	23
Mediastinal tumor	18	19	18
Others	46	21	38
Total	261	266	278

Operative Method for Primary Lung Carcinoma
	1995	1996	1997
Lung resection	137	167	161
Pneumonectomy	4	7	9
Lobectomy	127	151	147
(Bronchoplasty)	(8)	(3)	(4)
Conservative resection	6	9	5
Thoracoscopic resection (including staging)	16	30	16
Others	13	10	15

Survival Rates for Resected Primary Lung Carcinoma
Stage	3-yr (%)	4-yr (%)
Stage I	87.8	80.8
Stage II	74.0	64.8
Stage IIIA	52.8	36.3
Stage IIIB	36.3	-
Stage IV	21.7	-

(K. Nagai, J. Yoshida)

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