This quarter, we examine a case in which a patient with locally advanced non-small cell lung cancer (NSCLC) had a complete pathologic response following radiation therapy and 2 cycles of cisplatin-pemetrexed, despite radiation being prescribed with palliative intent. This summary provides an overview of the case report written by Chirillo et al.

Chirillo et al’s case describes a 75-year-old man with neuropathic chest and right shoulder pain with functional impairment found to have locally advanced non-small cell lung carcinoma.1 This patient’s initial treatment plan included neoadjuvant chemotherapy and radiation, but due to increasing pain, worsening functional status, and difficulty maintaining the position required for definitive radiation therapy, his treatment plan was converted to palliative radiation (8 Gy ×2 fractions) between the 2nd and 3rd cycles of cisplatin-pemetrexed and surgical resection. Upon histopathologic evaluation of this patient’s resected lung tumor, he was found to unexpectedly have a complete pathologic response.

This case is notable due to the patient’s complete pathologic response to a relatively low palliative radiation therapy regimen (8 Gy ×2) Figure 1. In the case study, Cirillo et al discuss the history of therapeutic approaches to treat NSCLC, including the current standard of care of 60 Gy. This case study is the first documented example of a purely palliative radiation therapy regimen inducing a complete pathologic response in NSCLC. Chirillo et al propose radiobiologic mechanisms underlying this response, including classic direct DNA damage, tumor vascular disruption and genetic suppression, and induction of immunogenic cell death. The impact of this case is in the suspicion it raises regarding how tumor and host-specific radiosensitivity factors may play an important role in challenging conventional dose-response paradigms.

Chirillo et al’s radiation treatment plan for locally advanced non-small cell lung cancer.
Figure 1. Chirillo et al’s radiation treatment plan for locally advanced non-small cell lung cancer.

Key Concepts

  1. Pancoast tumor: Superior sulcus tumors (also referred to as Pancoast tumors) are a subset of NSCLCs located in the apex of the lung that invade parietal pleura and cause pain, paresthesia, or other neurologic dysfunction. Pancoast tumors may invade adjacent muscles, upper ribs, thoracic vertebral bodies, subclavian vessels, the inferior portion of the brachial plexus, and the upper end of the thoracic autonomic chain (causing Horner syndrome).2

  2. Locally advanced NSCLC: Comprising about one-third of NSCLCs upon diagnosis, lung cancers of this stage span a wide spectrum of presentations including significant tumor burden (T3-T4, >7 cm and/or invading many possible nearby organs, or with separate tumor nodules in the same lung but different lobe) and nodal involvement (ipsilateral or contralateral mediastinal, subcarinal, contralateral mediastinal, or any scalene or supraclavicular involvement).3

  3. Neoadjuvant chemoradiation therapy: Chemotherapy and radiation given to shrink a tumor before the main treatment, typically surgery.4

  4. Palliative radiation therapy: Radiation therapy provided with the goal of symptomatic relief from primary tumor burden or metastatic lesions.5

  5. Complete pathologic response: Lack of all signs of cancer in tissue samples removed following a treatment.6