Management[edit]
Main article: Treatment of lung cancer
Treatment for lung cancer depends on the cancer's specific cell type, how far it has spread, and the person's performance status. Common treatments include palliative care,[84]surgery, chemotherapy, and radiation therapy.[1] Targeted therapy of lung cancer is growing in importance for advanced lung cancer.
Surgery[edit]
Main article: Lung cancer surgery
If investigations confirm NSCLC, the stage is assessed to determine whether the disease is localized and amenable to surgery or if it has spread to the point where it cannot be cured surgically. CT scan and positron emission tomography are used for this determination.[1] If mediastinal lymph node involvement is suspected, mediastinoscopy may be used to sample the nodes and assist staging.[85] Blood testsand pulmonary function testing are used to assess whether a person is well enough for surgery.[14] If pulmonary function tests reveal poor respiratory reserve, surgery may not be a possibility.[1]
In most cases of early-stage NSCLC, removal of a lobe of lung (lobectomy) is the surgical treatment of choice. In people who are unfit for a full lobectomy, a smaller sublobar excision (wedge resection) may be performed. However, wedge resection has a higher risk of recurrence than lobectomy.[86] Radioactive iodine brachytherapy at the margins of wedge excision may reduce the risk of recurrence.[87]Rarely, removal of a whole lung (pneumonectomy) is performed.[86] Video-assisted thoracoscopic surgery (VATS) and VATS lobectomyuse a minimally invasive approach to lung cancer surgery.[88] VATS lobectomy is equally effective compared to conventional open lobectomy, with less postoperative illness.[89]
In SCLC, chemotherapy and/or radiotherapy is typically used.[90] However the role of surgery in SCLC is being reconsidered. Surgery might improve outcomes when added to chemotherapy and radiation in early stage SCLC.[91]
Radiotherapy[edit]
Radiotherapy is often given together with chemotherapy, and may be used with curative intent in people with NSCLC who are not eligible for surgery. This form of high-intensity radiotherapy is called radical radiotherapy.[92] A refinement of this technique is continuous hyperfractionated accelerated radiotherapy (CHART), in which a high dose of radiotherapy is given in a short time period.[93]Postoperative thoracic radiotherapy generally should not be used after curative intent surgery for NSCLC.[94] Some people with mediastinal N2 lymph node involvement might benefit from post-operative radiotherapy.[95]
For potentially curable SCLC cases, chest radiotherapy is often recommended in addition to chemotherapy.[8]
If cancer growth blocks a short section of bronchus, brachytherapy (localized radiotherapy) may be given directly inside the airway to open the passage. Compared to external beam radiotherapy, brachytherapy allows a reduction in treatment time and reduced radiation exposure to healthcare staff.[96] Evidence for brachytherapy, however, is less than that for external beam radiotherapy.[97]
Prophylactic cranial irradiation (PCI) is a type of radiotherapy to the brain, used to reduce the risk of metastasis. PCI is most useful in SCLC. In limited-stage disease, PCI increases three-year survival from 15% to 20%; in extensive disease, one-year survival increases from 13% to 27%.[98]
Recent improvements in targeting and imaging have led to the development of stereotactic radiation in the treatment of early-stage lung cancer. In this form of radiotherapy, high doses are delivered over a number of sessions using stereotactic targeting techniques. Its use is primarily in patients who are not surgical candidates due to medical comorbidities.[99]
For both NSCLC and SCLC patients, smaller doses of radiation to the chest may be used for symptom control (palliative radiotherapy).[100]
Chemotherapy[edit]
The chemotherapy regimen depends on the tumor type.[8] Small-cell lung carcinoma (SCLC), even relatively early stage disease, is treated primarily with chemotherapy and radiation.[101] In SCLC, cisplatin and etoposide are most commonly used.[102] Combinations withcarboplatin, gemcitabine, paclitaxel, vinorelbine, topotecan, and irinotecan are also used.[103][104] In advanced non-small cell lung carcinoma (NSCLC), chemotherapy improves survival and is used as first-line treatment, provided the person is well enough for the treatment.[105] Typically, two drugs are used, of which one is often platinum-based (eithercisplatin or carboplatin). Other commonly used drugs are gemcitabine, paclitaxel, docetaxel,[106][107] pemetrexed,[108] etoposide or vinorelbine.[107]
Adjuvant chemotherapy refers to the use of chemotherapy after apparently curative surgery to improve the outcome. In NSCLC, samples are taken of nearby lymph nodes during surgery to assist staging. If stage II or III disease is confirmed, adjuvant chemotherapy improves survival by 5% at five years.[109][110] The combination of vinorelbine and cisplatin is more effective than older regimens.[110] Adjuvant chemotherapy for people with stage IB cancer is controversial, as clinical trials have not clearly demonstrated a survival benefit.[111][112] Chemotherapy before surgery in NSCLC that can be removed surgically also appears to improve outcomes.[113]
Chemotherapy may be combined with palliative care in the treatment of the NSCLC. In advanced cases, appropriate chemotherapy improves average survival over supportive care alone, as well as improving quality of life.[114] With adequate physical fitness maintaining chemotherapy during lung cancer palliation offers 1.5 to 3 months of prolongation of survival, symptomatic relief, and an improvement in quality of life, with better results seen with modern agents.[115][116] The NSCLC Meta-Analyses Collaborative Group recommends if the recipient wants and can tolerate treatment, then chemotherapy should be considered in advanced NSCLC.[105][117]
Targeted therapy[edit]
Several drugs that target molecular pathways in lung cancer are available, especially for the treatment of advanced disease. Erlotinib, gefitinib and afatinib inhibit tyrosine kinaseat the epidermal growth factor receptor. Denosumab is a monoclonal antibody directed against receptor activator of nuclear factor kappa-B ligand. It may be useful in the treatment of bone metastases.[118]
Palliative care[edit]
Palliative care when added to usual cancer care benefits people even when they are still receiving chemotherapy.[119] These approaches allow additional discussion of treatment options and provide opportunities to arrive at well-considered decisions.[120][121] Palliative care may avoid unhelpful but expensive care not only at the end of life, but also throughout the course of the illness. For individuals who have more advanced disease, hospice care may also be appropriate.[14][121]
Prognosis[edit]
| Clinical stage | Five-year survival (%) | |
|---|---|---|
| Non-small-cell lung carcinoma | Small-cell lung carcinoma | |
| IA | 50 | 38 |
| IB | 47 | 21 |
| IIA | 36 | 38 |
| IIB | 26 | 18 |
| IIIA | 19 | 13 |
| IIIB | 7 | 9 |
| IV | 2 | 1 |
Of all people with lung cancer in the US, 16.8% survive for at least five years after diagnosis.[10][122] In England, between 2005 and 2009, overall five-year survival for lung cancer was less than 10%.[123] Outcomes are generally worse in the developing world.[124] Stage is often advanced at the time of diagnosis. At presentation, 30–40% of cases of NSCLC are stage IV, and 60% of SCLC are stage IV.[8] Survival for lung cancer falls as the stage at diagnosis becomes more advanced: the English data suggest that around 70% of patients survive at least a year when diagnosed at the earliest stage, but this falls to just 14% for those diagnosed with the most advanced disease.[125]
Prognostic factors in NSCLC include presence or absence of pulmonary symptoms, tumor size, cell type (histology), degree of spread (stage) and metastases to multiple lymph nodes, and vascular invasion. For people with inoperable disease, outcomes are worse in those with poor performance status and weight loss of more than 10%.[126] Prognostic factors in small cell lung cancer include performance status, gender, stage of disease, and involvement of the central nervous system or liver at the time of diagnosis.[127]
For NSCLC, the best prognosis is achieved with complete surgical resection of stage IA disease, with up to 70% five-year survival.[128] For SCLC, the overall five-year survival is about 5%.[1] People with extensive-stage SCLC have an average five-year survival rate of less than 1%. The average survival time for limited-stage disease is 20 months, with a five-year survival rate of 20%.[2]
According to data provided by the National Cancer Institute, the median age at diagnosis of lung cancer in the United States is 70 years,[129] and the median age at death is 72 years.[130] In the US, people with medical insurance are more likely to have a better outcome.[131]
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