Spontaneous regression of cancer is an extremely rare phenomenon, and it has been described in only a few cases of pulmonary cancer. We report a case of complete spontaneous regression of squamous-cell lung cancer (SCLC) following a core needle biopsy in a 67-year-old female patient with two previous lung cancers and concomitant follicular lymphoma. The patient was diagnosed with SCLC after 4 core needle biopsies from a nodule in the left upper lobe and at the same time suspected of having follicular lymphoma. Treatment for the lung cancer was delayed by approximately 8 weeks because the diagnosis of lymphoma was both challenging and time-consuming. A computed tomography scan was performed in relation to the scheduled treatment for SCLC, showing that the pulmonary nodule had disappeared completely. Most other cases of spontaneous regression of lung cancer hint at the involvement of immunological factors, and this case possibly involves a combination of mechanical and local immunological factors. Genetic and immunological analysis of patients showing spontaneous regression of cancers could provide valuable information.

No abstract

IntroductionTreatment with inhaled corticosteroids (ICS) is a widely used treatment in chronic obstructive pulmonary disease. The main effects include a reduction in the number of exacerbations and, for some patients, an increase in expected mortality. Unfortunately, the treatment is also linked to an increased risk of pneumonia, and very little is known about which patients experience this increased risk. There is a need for identification of patient characteristics associated with increased risk of pneumonia and treatment with ICS.Methods and analysisThis is a register-based cohort study that uses the nationwide Danish registers. Data from several registers in the years 2008–2018 will be merged on an individual level using the personal identification numbers that are unique to every citizen in Denmark. Clusters based on pneumonia incidence and ICS treatment patterns will be explored with a sequence analysis in a 3-year follow-up period.Ethics and disseminationThis is a register-based study and research ethics approval is not required according to Danish Law and National Ethics Committee Guidelines. The results will be submitted to peer-reviewed journals and reported at appropriate national and international meetings.

No abstract