Editing Lung cancer (section)

===Staging===
{{see also|Lung cancer staging}}
{| class="wikitable floatright" style="text-align:right;font-size:90%;margin-left:1em;background:#E5AFAA;"
|+ Stage group according to TNM classification in lung cancer{{sfn|Lim|Ridge|Nicholson|Mirsadraee|2018|loc="Table 5: Overall stage based on T, N, and M descriptors"}}
|-
! TNM
! Stage group
|-
| T1a N0 M0
| IA1
|-
| T1b N0 M0
| IA2
|-
| T1c N0 M0
| IA3
|-
| T2a N0 M0
| IB
|-
| T2b N0 M0
| IIA
|-
| T1–T2 N1 M0
| rowspan="2" | IIB
|-
| T3 N0 M0
|-
| T1–T2 N2 M0
| rowspan="3" | IIIA
|-
| T3 N1 M0
|-
| T4 N0–N1 M0
|-
| T1–T2 N3 M0
| rowspan="2" | IIIB
|-
| T3–T4 N2 M0
|-
| T3–T4 N3 M0
| IIIC
|-
| Any T, any N, M1a–M1b
| IVA
|-
| Any T, any N, M1c
| IVB
|}

Lung [[cancer staging]] is an assessment of the degree of spread of the cancer from its original source. It is one of the factors affecting both the [[prognosis]] and the treatment of lung cancer.<ref name=ACS-SCLC-Stage>{{cite web|url=https://www.cancer.org/cancer/lung-cancer/detection-diagnosis-staging/staging-sclc.html |accessdate=2 December 2022 |title=Small Cell Lung Cancer Stages |publisher= [[American Cancer Society]] |date=1 October 2019}}</ref>

SCLC is typically staged with a relatively simple system: limited stage or extensive stage. Around a third of people are diagnosed at the limited stage, meaning cancer is confined to one side of the chest, within the scope of a single [[radiotherapy]] field.<ref name=ACS-SCLC-Stage/> The other two thirds are diagnosed at the "extensive stage", with cancer spread to both sides of the chest, or to other parts of the body.<ref name=ACS-SCLC-Stage/>

NSCLC – and sometimes SCLC – is typically staged with the [[American Joint Committee on Cancer]]'s [[TNM staging system|Tumor, Node, Metastasis (TNM) staging system]].<ref name=ACS-NSCLC-Stage>{{cite web|url=https://www.cancer.org/cancer/lung-cancer/detection-diagnosis-staging/staging-nsclc.html |accessdate=2 December 2022 |title=Non-small Cell Lung Cancer Stages |publisher= [[American Cancer Society]] |date=1 October 2019}}</ref> The size and extent of the tumor (T), spread to regional lymph nodes (N), and distant metastases (M) are scored individually, and combined to form stage groups.{{sfn|Horn|Iams|2022|loc="Staging System for Non-Small-Cell Lung Cancer"}}

Relatively small tumors are designated T1, which are subdivided by size: tumors ≤ 1 [[centimeter]] (cm) across are T1a; 1–2 cm T1b; 2–3 cm T1c. Tumors up to 5 cm across, or those that have spread to the [[Pulmonary pleurae|visceral pleura]] (tissue covering the lung) or [[main bronchi]], are designated T2. T2a designates 3–4 cm tumors; T2b 4–5 cm tumors. T3 tumors are up to 7 cm across, have multiple nodules in the same [[Lung#Lobes|lobe]] of the lung, or invade the [[chest wall]], diaphragm (or the [[phrenic nerve|nerve that controls it]]), or area around the heart.{{sfn|Horn|Iams|2022|loc="Staging System for Non-Small-Cell Lung Cancer"}}{{sfn|Pastis|Gonzalez|Silvestri|2022|loc="Eight Edition Lung Cancer Stage Classification"}} Tumors that are larger than 7 cm, have nodules spread in different lobes of a lung, or invade the [[mediastinum]] (center of the chest cavity), heart, [[great vessels|largest blood vessels]] that supply the heart, [[trachea]], [[esophagus]], or [[Vertebral column|spine]] are designated T4.{{sfn|Horn|Iams|2022|loc="Staging System for Non-Small-Cell Lung Cancer"}}{{sfn|Pastis|Gonzalez|Silvestri|2022|loc="Eight Edition Lung Cancer Stage Classification"}} [[Lymph node]] staging depends on the extent of local spread: with the cancer metastasized to no lymph nodes (N0), pulmonary or [[hilar nodes]] (along the bronchi) on the same side as the tumor (N1), [[Mediastinal lymph node|mediastinal]] or subcarinal lymph nodes (in the middle of the lungs, N2), or lymph nodes on the opposite side of the lung from the tumor (N3).{{sfn|Pastis|Gonzalez|Silvestri|2022|loc="Eight Edition Lung Cancer Stage Classification"}} Metastases are staged as no metastases (M0), nearby metastases (M1a; the space around the lung or the heart, or the opposite lung), a single distant metastasis (M1b), or multiple metastases (M1c).{{sfn|Horn|Iams|2022|loc="Staging System for Non-Small-Cell Lung Cancer"}}

These T, N, and M scores are combined to designate a stage grouping for the cancer. Cancer limited to smaller tumors is designated stage I. Disease with larger tumors or spread to the nearest lymph nodes is stage II. Cancer with the largest tumors or extensive lymph node spread is stage III. Cancer that has metastasized is stage IV. Each stage is further subdivided based on the combination of T, N, and M scores.{{sfn|Horn|Iams|2022|loc="Table 78–6 TNM Stage Groupings, Eighth Edition"}}

{| class="wikitable" style="text-align:center;font-size:90%;margin-left:1em;background:#E5AFAA;"
|+ TNM classification in lung cancer<ref>{{cite web | title=Lung Cancer TNM staging summary|edition=8th | publisher=International Association for the Study of Lung Cancer | url=https://www.iaslc.org/sites/default/files/wysiwyg-assets/iaslc_8th_posters_24x36_2018_final_version_1.pdf | access-date=30 May 2018 | archive-url=https://web.archive.org/web/20180617220133/https://www.iaslc.org/sites/default/files/wysiwyg-assets/iaslc_8th_posters_24x36_2018_final_version_1.pdf | archive-date=17 June 2018 | url-status=dead }}</ref>
|-
|
{| class="wikitable"
|-
! colspan="3" | T: Primary tumor
|-
| T0
| colspan="2" | No primary tumor
|-
| Tis
| colspan="2" | [[Carcinoma in situ]]
|-
| T1
| colspan="2" | Tumor ≤ 3&nbsp;cm across, surrounded by lung or visceral pleura
|-
| rowspan="4" |
| T1mi
| Minimally invasive adenocarcinoma
|-
| T1a
| Tumor ≤ 1&nbsp;cm across
|-
| T1b
| Tumor > 1&nbsp;cm but ≤ 2&nbsp;cm across
|-
| T1c
| Tumor > 2&nbsp;cm but ≤ 3&nbsp;cm across
|-
| rowspan="4" | T2
| rowspan="4" | Any of:
| Tumor size > 3&nbsp;cm but ≤ 5&nbsp;cm across
|-
| Involvement of the main bronchus but not the carina
|-
| Invasion of visceral pleura
|-
| Atelectasis/[[obstructive pneumonitis]] extending to the [[Hilum (anatomy)|hilum]]
|-
| rowspan="2" |
| T2a
| Tumor > 3&nbsp;cm but ≤ 4&nbsp;cm across
|-
| T2b
| Tumor > 4&nbsp;cm but ≤ 5&nbsp;cm across
|-
| rowspan="3" | T3
| rowspan="3" | Any of:
| Tumor size > 5&nbsp;cm but ≤ 7&nbsp;cm across
|-
| Invasion into the chest wall, [[phrenic nerve]], or parietal [[pericardium]]
|-
| Separate tumor nodule in the same lobe
|-
| rowspan="3" | T4
| rowspan="3" | Any of:
| Tumor size > 7&nbsp;cm
|-
| Invasion of the diaphragm, mediastinum, heart, [[great vessels]], [[trachea]], [[Carina of trachea|carina]], [[recurrent laryngeal nerve]], [[esophagus]], or [[vertebral body]]
|-
| Separate tumor nodule in a different lobe of the same lung
|}
| style="vertical-align:top;" |
{| class="wikitable"
|-
! colspan="3" | N: Lymph nodes
|-
| N0
| colspan="2" | No lymph node metastasis
|-
| N1
| colspan="2" | Metastasis to [[ipsilateral]] peribronchial or hilar lymph nodes
|-
| N2
| colspan="2" | Metastasis to ipsilateral mediastinal or subcarinal lymph nodes
|-
| rowspan="2" | N3
| rowspan="2" | Any of:
| Metastasis to scalene or supraclavicular lymph nodes
|-
| Metastasis to contralateral hilar or mediastinal lymph nodes
|}
| style="vertical-align:top;" |
{| class="wikitable"
|-
! colspan="3" | M: Metastasis
|-
| M0
| colspan="2" | No distant metastasis
|-
| rowspan="3" | M1a
| rowspan="3" | Any of:
| Separate tumor nodule in the other lung
|-
| Tumor with pleural or pericardial nodules
|-
| Malignant [[Pleural effusion|pleural]] or [[pericardial effusion]]
|-
| M1b
| colspan="2" | A single metastasis outside the chest
|-
| M1c
| colspan="2" | Two or more metastases outside the chest
|}
|}