Revised (8th) Edition of TNM Staging System for Lung Cancer

Journal of Thoracic Oncology • Volume 10, Number 9, Supplement 2, September 2015

LUNG CANCER: IASLC GLOBAL INITIATIVES
TUESDAY, SEPTEMBER 8, 2015 - 08:15-09:45
PLEN02.02 Revised (8th) Edition of TNM Staging System for Lung Cancer
Ramon Rami-Porta Thoracic Surgery, Hospital Universitari Mutua Terrassa, Terrassa/Spain

The changes introduced in the 7th edition of the tumour, node and metastasis (TNM)
classification for lung cancer derived from the analyses of the International Association
for the Study of Lung Cancer (IASLC) database. These analyses were conducted by
the members of the IASLC Staging and Prognostic Factors Committee (SPFC) and the
biostatisticians of Cancer Research And Biostatistics (CRAB). For the first time in the
history of the TNM classification for lung cancer, the 7th edition was based on a truly
international database of more than 80,000 evaluable patients collected in 45 different
sources in 20 countries and treated with all treatment modalities from 1990 to 2000. (1)
The changes recommended by the IASLC were accepted by the Union for International
Cancer Control (UICC) and by the American Joint Committee on Cancer (AJCC) and were
eventually published in their staging manuals. With this involvement of the IASLC in the
revision of the TNM classification for lung cancer, the IASLC became the most important
provider of data to the UICC and the AJCC for future editions of the classification. A
similar process was used for the revision of the 7th edition into the 8th edition. The IASLC
made an international call for submission of more data to the IASLC database. (2) The
resulting international contribution amounted to more than 77,000 evaluable patients
diagnosed with either non-small cell lung cancer (70,967 patients) or small cell lung
cancer (6,189 patients) from 1990 to 2010. They were submitted from 35 different
databases located in 16 countries in Europe, Asia, North and South America, and
Australia. (3) The different subcommittees of the Lung Cancer Domain of the IASLC SPFC
were in charge of analysing the data pertaining to the T, the N and the M component of the
classification, as well as the stages and the small cell lung cancer. For the T component,
the prognostic impact of the T descriptors was analysed in five different populations:
pT1-4N0M0R0, pT1-4anyNM0R0, pT1-4anyNM0anyR, i.e., including incomplete
resections, either microscopically incomplete, R1, or macroscopically incomplete, R2;
and cT1-4N0M0 and cT1-4anyNM0. Survival analyses were completed with univariate
and multivariate analyses adjusted by histological type, gender, region and age. The
main results showed that the capacity of tumour size to separate tumours of different
prognosis was greater than that shown in previous analyses, and that its influence could
be spread to all T categories; the role of visceral pleura invasion as a T2 descriptor
was confirmed; the prognostic impact of endobronchial location less than 2 cm from
the carina (T3 in 7th edition) and of total atelectasis/pneumonitis (T3 in 7th edition) was
found to be similar to that of their T2 counterparts; diaphragm invasion was found to
have worse prognosis than that of other T3 descriptors; and mediastinal pleura invasion
was found to be scarcely used as a T descriptor. (4) For the N component, the present N
descriptors (N0, N1, N2 and N3) were found to separate tumours of different prognosis
in clinically and pathologically (both in the R0 and any R populations) staged tumours.
The impact of tumour burden in the lymph nodes could also be assessed when survival
was analysed according to the number of nodal stations, but this could only be analysed
in the population of patients who had undergone tumour resection and systematic nodal
dissection, and could not be validated at clinical staging. (5) For the M component, the
7th edition M1a descriptors were validated, as all showed similar survival. However,
when the M1b descriptors were analysed in detail, single metastasis (one metastasis
in one organ) had better prognosis than multiple metastases in one or several organs.
(6) Table 1 shows the changes recommended by the IASLC SPFC based on the analyses
of the new IASLC database. The described changes implied some modifications in the
stage grouping, creating more stages for early and advanced disease, (7) and were
also applicable to small-cell lung cancer. (8) The IASLC recommendations emphasize the
prognostic impact of tumour size; simplify the T descriptors by combining some of them;
maintain the current N descriptors; separate tumours with single metastasis in a distinct
group; and establish more stage groupings to refine prognosis based on anatomic
extent of disease. They improve our capacity to indicate prognosis, which is one of the
objectives of the TNM classification, and, therefore, they should be implemented in the
8th edition of the TNM classification. Table 1

References
1. Goldstraw P, Crowley JJ. The International Association for the Study of Lung Cancer international staging project on lung cancer. J Thorac Oncol 2006; 1: 281-286.
2. Giroux DJ, Rami-Porta R, Chansky K et al. The IASLC Lung Cancer Staging Project: data elements for the prospective project. J Thorac Oncol 2009; 4: 679-683.
3. Rami-Porta R, Bolejack V, Giroux DJ et al. The IASLC Lung Cancer Staging Project: the new database to inform the 8th edition of the TNM classification of lung cancer. J Thorac Oncol 2014; 9: 1618-1624.
4. Rami-Porta R, Bolejack V, Crowley J et al. The IASLC Lung Cancer Staging Project: proposals for the revisions of the T descriptors in the forthcoming eighth edition of the TNM classification for lung cancer. J Thorac Oncol 2015;10:990-1003.
5. Asamura H et al. J Thorac Oncol 2015; in preparation.
6. Eberhardt WEE et al. J Thorac Oncol 2015; in preparation.
7. Golstraw P et al. J Thorac Oncol 2015; in preparation. 8. Nicholson AG et al. J Thorac Oncol 2015; in preparation.

Keywords: TNM classification, lung cancer, lung cancer staging

환자, 의사 관계

좋은 의사는 어떤 의사일까?

환자 입장에서는 뉴스, 방송에 보도되는 명의들을 먼저 떠올리게 될 것이다. 식당을 고를 때도 맛집으로 소문난 곳을 가야 마음이 놓이는데, 하물며 내 몸을 고치는 의사를 고를 때는 당연히 명의라고 소문난 의사를 찾을 수 밖에 없다. 하지만, 맛집에 가서 실망할 때가 있는 것처럼 아무리 명의라고 해도 찾아온 환자, 보호자들을 모두 만족시킬 수는 없을 듯 하다. 친절한 맛집을 본적이 별로 없다. 때로는 이름없는 식당보다 못한 음식을 내놓는 맛집에 실망할 때도 있다. 나는 과연 어떤 위치에 자리잡은 의사일까?

병을 잘 고치는 의사가 좋은 의사일까? 설명을 잘 하는 의사? 친절한 의사? 환자, 보호자들로서는 의사만큼의 전문지식을 갖추는 것이 불가능하다. 요즘처럼 세부전문과목이 나뉘어진 시대에는 의사들끼리도 다른 분야는 잘 알 수가 없다. 흉부외과 의사라고 해도 폐수술을 하는 의사로 오래 살다 보면 심장수술에 대한 기억도 희미해질 수 밖에 없다.

3분도 되지 않는 외래진료 시간에 과연 환자, 보호자들을 만족시키는 것이 가능할까?
아직도 나는 계속하여 환자, 보호자들에게 배우고 있다. 나를 찾아준 환자, 보호자들에게 감사하고, 그들의 이야기를 우선적으로 귀담아 듣다 보면 어떻게 해야 할지 길이 보인다. 내 주장과 지시만 전달하는 것이 아니라, 몸과 마음이 아픈 사람들의 이야기를 들어주고, 공감하려는 것부터 제대로 해내고 싶다.

Single port VATS lobectomy

일반흉부 수술에서 VATS는 이미 표준적 수술법으로 자리잡았다. 일부 surgeon은 2-4개의 port 대신 단 하나의 port 만으로 VATS를 시행하는 single port VATS(uniportal VATS)를 시도하기 시작하였다. 미용적인 면에서, 절개 길이를 줄이고, port 숫자를 줄이는 것은 효과적이다. 하지만, 통증 면에서 과연 2~4개의 port를 사용하는 multi-port VATS 에 비해 얼마나 효과적인지는 아직 알려진바 없다. 개흉술에 비하여 VATS는 분명 통증을 효과적으로 감소시키지만, multi-port VATS와 single port VATS 간에 얼마나 차이가 있을까? 현장에서 느끼는 바로는 그 차이가 크지 않은 듯 하다. 한편 폐암에서 과연 single port로 수술하는 것이 정당한가에 대한 의문도 아직 해결되지 않았다. single port VATS에서 암 수술의 원칙, 즉 충분히 림프절을 절제하고, 암세포의 seeding을 만들지 않는 등의 원칙을 제대로 지킬 수 있을지는 단순한 수술완료 뿐이 아니라, 장기성적도 검토되어야 한다. 따라서, 자칫 환자를 위험에 빠뜨리거나 암 수술의 원칙을 견지할 수 없는 상황(환자 상태, surgeon의 수술경험 등 모두 고려)이라면 multi-port VATS 또는 open thoracotomy가 기본이 되어야 한다. 암이 아닌, benign lung disease라면 single port VATS는 매력적인 수술방법이다. 수술 중 문제 없이 lobectomy를 완료하고, 합병증 없이 퇴원한다면, sinlge port VATS lobectomy를 받은 환자들은 매우 행복해 할 것이다.