SESSION TITLE: Lung Cancer Student/Resident Case Report Posters
SESSION TYPE: Student/Resident Case Report Poster
PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM
INTRODUCTION: Spontaneous regression (SR) of cancer, is defined as partial or complete disappearance of a tumor without any or adequate treatment is extremely rare, occurring in only about 1/100,000 cases of diagnosed cancers. Here we report the first known case of complete SR of a bronchial carcinoid tumor.
CASE PRESENTATION: Mr. HN is a 79 year-old Asian male who presents to pulmonary clinic for a mass seen on chest x-ray in 2009. The mass was a 3cm, well circumscribed lesion in left lower lobe of the lung. The patient then underwent CT guided biopsy in 2009 with pathology showing benign spindle cell carcinoid tumor. Definitive treatment is surgical resection, however, the patient opted for annual radiographic surveillance. Radiographs in 2012 showed the lesion had decreased in size, and continued with this trend. A CT scan in January of 2015 showed only residual scar tissue at the site of the previous mass. Follow-up visits with the patient confirmed that he did not undergo any medical, surgical or radiation-based treatment since time of biopsy diagnosis. Nor was the patient diagnosed with any new medical conditions during this time that could have affected the tumor. The patient did admit to a new diet of juicing asparagus daily.
DISCUSSION: SR of cancer is extremely rare and poorly understood. The most commonly accepted mechanism is thought to be immune mediated as many cases occured after immune provoking events such as infections, pyrexia, trauma, surgery, and blood transfusions. SR of cancers have also been linked to hormonal changes seen with pregnancy, oral contraceptive use, and severe dietary changes. Such cases involved hormonally responsive breast and prostate cancers. In our patient the most likely mechanism for complete SR of his tumor is probably immune mediated. It is unclear from his medical history if there was an immune inciting event during this period. Many of the more recent cases of SR of primary thoracic tumors saw SR following biopsy of the tumor. It is thought to be mediated by tumor cytotoxic CD8+ cell infiltration of the biopsied lesion. The only other documented case of SR of a bronchial carcinoid tumor was in a pregnant patient with the possibility that regression was hormonally mediated. However, in our elderly male patient, this is a less likely explanation.
CONCLUSIONS: Our understanding of SR of cancer is limited and speculative at best. However, it is important for clinicians to know that such rare events do occur and may influence management of indolent tumors. Report such cases can further our understanding of this phenomenon.
Reference #1: Challis GB and Stam HJ. The Spontaneous Regression of Cancer: A Review of Cases from 1900 to 1987. Acta Oncologica 1990; Vol. 29 Fasc. 5.
Reference #2: Kumar T, Patel N, Talwar A. Spontaneous Regression of Thoracic Malignancies. Resp Med 2010; 104 1543-1550.
Reference #3: Lusto R, Koikkalainen K, Sipponen P. Spontaneous Regression of a Bronchial Carcinoid Tumor Following Pregnancy. Ann Chirurgiae et Gyn Fenniae 1974; 63:342-345.
DISCLOSURE: The following authors have nothing to disclose: Diep Dao, Joseph Resnikoff
No Product/Research Disclosure Information