Pseudoprogression of Lung Cancer after Concomitant Chemoradiotherapy

Abstract

We observed re-enlargement of a squamous cell carcinoma without recurrence. The tumour regressed markedly after concomitant chemoradiotherapy, but within 1 month, we supposed that the tumour had enlarged again and resection was performed. The resected tissue showed evidence of haemorrhage and several lymphocytes and macrophages, but no malignant cells were detected. We herein report a rare case of lung cancer showing a pathological complete response despite re-enlargement of tumour lesion.

Diagnostic Dilemma of Pseudoprogression in the Treatment of Newly Diagnosed Glioblastomas: The Role of Assessing Relative Cerebral Blood Flow Volume and Oxygen-6-Methylguanine-DNA Methyltransferase Promoter Methylation Status

“…The histopathologic examination of pseudoprogression demonstrates findings similar to those in radiation necrosis, such as necrosis, edema, and gliosis in addition to endothelial thickening, hyalinization, thrombosis, and occlusion of vessels. [1][2][3][4][5][6] These results could be explained by chemoradiotherapy possibly causing a high degree of tumor cell and endothelial cell killing, resulting in the acceleration of the radiation necrosis. 15,19 However, even in second-look surgery, differentiation between pseudoprogression and real tumor progression is very difficult because pseudoprogression can still involve residual infiltrated tumor cells, often leading to erroneous interpretation by the pathologist.…”

“…Because of recent advances in the diagnostic techniques, new or progressive enhancing lesions on MR images demonstrating a transient increase in tumor enhancement without real progression, so-called pseudoprogression, after CCRT have been widely recognized. [1][2][3][4][5][6][7][8][9] Pseudoprogression can spontaneously decrease in size or stabilize without additional treatments without developing neurologic symptoms. New or enlarging enhanced lesions after CCRT, suggesting either real tumor progression or pseudoprogression and affecting 20%-40% of all treated lesions, constitute a clinically relevant diagnostic dilemma in patients with newly diagnosed GBMs.…”

Mechanism and non-mechanism based imaging biomarkers for assessing biological response to treatment in non-small cell lung cancer

“…Frequently, up to 6e12 months following treatment, early pneumonitis and later dense mass-like consolidation and nodularity impair the ability of CT based RECIST and 18 FDG-PET CT to differentiate residual or recurrent viable tumour from treatment related inflammation, 'pseudoprogression' or evolving fibrosis, especially following stereotactic radiotherapy (Fig. 5) [15,70,72,74,75].…”

The Challenges Faced in Developing Novel Drug Radiation Combinations in Non-small Cell Lung Cancer

“…Pseudo-progression of the apparent disease in the irradiated field is a well-recognised clinical entity after both conventional chemoradiotherapy and stereotactic ablative body radiotherapy [38,39]. Any potential studies in this area will need have mechanisms to take pseudo-progression into account and may need to consider the more robust end-point of overall survival when assessing clinical efficacy.…”