Medical/ Surgical Treatment Options for Small- Cell Lung Cancer

Introduction:

Cancer is a very challenging illness that affects many people. An estimated 1.3 million individuals die of lung cancer each year; 13-20% of that compromise of small-cell lung cancer (SCLC), and about 80% is non-small cell lung cancer (NSCLC).¹ It is hard for patients to fight lung cancer knowing mortality ratio is high and treatment options are so limited. Studies and research is partial. There is an insufficient quantity of SCLC tumor tissue to produce consistent studies to test effectiveness of treatments. SCLC is known to be the most aggressive lung cancer subtype and is associated with cigarette smoking. Without treatment, individuals have about 3-6 months to live. With treatment life can increase by 1-2 years. In this paper, the limited medical treatment options for SCLC will be discussed.

Etiology:

SCLC is a malignant epithelial neoplasm usually consisting of SCLC can be difficult to distinguish from other lung malignancies, therefore, often times immunohistochemistry is used to detect cytokeratins (epithelial markers) and neuroendocrine markers to distinguish SCLC from other lung cancers. Staging can be based on total body CT, PET, mediastinoscopy or endoscopic ultrasound needle aspiration. Patients present with shortness of breath, weight loss, increased sputum production, chest pain suggesting pleural involvement or chest wall invasion. Hoarseness from compression on the left laryngeal nerve can be present. Horners syndrome is also seen in some patients and has symptoms of miosis, ptosis, and anhidrosis over face and forehead.² It is important to determine SCLC as soon as possible to avoid metastasis.

Research:

American College of Chest Physicians (ACCP) and National Comprehensive Cancer Network (NCCN) recommend that only patients with Stage I SCLC should be considered for surgery. A lobectomy can improve local control and long-term survival by removing the lung tissue and lymph node around affected site.¹ Chemotherapy should always be followed after surgery. Controversies exist regarding the dosages and optimal timing of chemotherapy.² If cancer metastasizes, most SCLCs are treated with chemotherapy, with six of platinum-based chemotherapy plus etoposide (Toposar or Veposid) or irinotecan (Camptosar). Radiation oncology has improved over the years and studies show better treatment results when thoracic radiotherapy (TRT) is combined with induction chemotherapy (IC). TRT treatment, also known as prophylactic cranial irritation (PCI), is prescribed to lower chances of cancer spreading to the brain. TRT is similar as getting an x-ray; different angles are used to aim for certain body structures, but in TRT the radiation is much more intense. If tumor is near important structures, TRT can be done with an advanced 3D technique; aiming precisely at the tumor to avoid reaching sensitive areas around.

One study tested the outcomes of 146 patients that received TRT before 2-3 cycles of chemotherapy to those that received TRT after 2-3 cycles of chemotherapy. Survival rate was calculated from the date of diagnosis to the date of death or last seen visit. Results showed better outcomes when TRT was administered before IC; overall survival was 29 months for the early TRT and 19.9 months for the late TRT group. These results might be because patients in the early TRT had a short duration between the start of chemotherapy and radiotherapy administration, and early TRT group received concurrent chemoradiotherapy. Previous research says that concurrent chemoradiotherapy is superior to a sequential regimen in the treatment of SCLC.³

A retrospective study evaluated . Ninety-six patients in group I that underwent surgery followed chemotherapy with thoracic radiotherapy (TRT). Surgical procedures included complete wedge resection, lobectomy or pneumectomy with lymphadenectomy. Forty-nine patients in group II were given the standard treatment with chemotherapy. Five- year survival was 57% for patients that underwent surgery, and only 31.7% for non-surgical therapy.⁴

Another approach to treating SCLC is the use of a potent alkulating agent, ifosfamide, in combination with carboplatin and etoposite (ICE). A study of patients aged 51-88 were treated with ICE from 2002 to 2014; 23% with limited disease (LD), and 37% with extensive disease with brain metastasis. Treatment was repeated every 3 weeks and continued until oxygen toxicity was unbearable for the body due to the side effects. Overall, this study’s results were consistent with previous studies; survival rate was ranging from 5.5% to 76.5% in the treatment of SCLC in the use of ICE; mean survival was 11.3 months; 20.6 months for LD and 9.3 months for ED. However, the toxicity levels were high even with dose adjustment. Patients experienced neutropenia, anemia, thrombocytopenia, vomiting and nausea. ⁵ Often times, treating late stage SCLC is not beneficial to patients especially if the cure just prolongs the pain and misery the patient has to go though. It is up to the patient to make that decision.

Synthesis:

All the above studies show treatment options for patients with SCLC are limited, especially when the cancer metastasis is in the brain. The studies included adult populations with an age average of 55-65. It is hard to determine effectiveness of treatments as some patients still smoked during treatments while others did not. In the retrospective study, the individuals that smoked had a higher rate of survival in group I of about 10%, but in group II that changed and patients that did not smoke had a higher survival rate of about 15%. It is hard to control people’s habits, especially the addictive ones such as smoking.

Conclusion:

The risk of lung cancer is proportional to cigarette pack-years smoked. Many patients know the consequences, yet still continue to smoke. SCLC is hard to treat, as it is systemic disease. Many factors play a key role in the progress especially patients themselves. Relapse occurs in most patients and survival is only up to 2 years even with treatment. Treatments are limited, but consistent studies show that surgery aims the longest survival rate. Thoracic radiotherapy (TRT) combined with induction chemotherapy (IC) also shows a prolonged survival rate. Ifosfamide alone and with combination with etoposide and carboplatic can be used in relapsed patients, however the toxicity is very high. In conclusion, findings are limited due to the occasional incidence of SCLC and small study population. Patients with SCLC often times die from multiple organ failure.

References

1. Ma PC. Neoplastic disorders of the lung. In: Ivor B, Griggs R, Wing E, Fitz G. Andreoli and Carpenter’s Cecil Essentials of Medicine, 9th edition. Philadelphia: Saunders Elsevier; 2015:266-270.
2. Veronesi, G., Bottoni, E., Finocchiaro, G., & Alloisio, M. (2015). When is surgery indicated for small-cell lung cancer? Lung Cancer (Amsterdam, Netherlands), 90(3), 582-589.
3. Zhu, H., Zhou, Z., Xue, Q., Zhang, X., He, J., & Wang, L. (2013). Treatment modality selection and prognosis of early stage small cell lung cancer: Retrospective analysis from a single cancer institute. European Journal of Cancer Care, 22(6), 789-796 8p.
4. Wang, P., Liu, W., Zhao, L., & Wang, P. (2015). Does the response to induction chemotherapy impact the timing of thoracic radiotherapy for limited-stage small-cell lung cancer? Thoracic Cancer, 6(5), 605-612 8p.
5. Lee, H. S., Lee, Y. G., Koo, D. H., Oh, S., Nam, H., Song, J. U., et al. (2015). Efficacy and safety of ifosfamide in combination with carboplatin and etoposide in small cell lung cancer. Cancer Chemotherapy and Pharmacology, 76(5), 933-937.