What Can Trigger Spontaneous Regression of Breast Cancer?

Abstract

Background: Spontaneous regression of tumors is a rare phenomenon in which cancer volume is reduced or, alternatively, a tumor completely disappears in the absence of any pharmacological treatment. This phenomenon has previously been described in several tumors, such as neuroblastomas, testicular malignancies, renal cell carcinomas, melanomas, and lymphomas. Spontaneous remission has also been documented in breast cancer; however, it represents an extremely rare and poorly understood phenomenon, with only a few reported cases in the literature. Methods: We herein report two cases of breast cancer that showed spontaneous tumor regression in the surgical specimen after a pathologically confirmed diagnosis of invasive breast cancer in core needle biopsy samples. Results: Macroscopically, both the surgical samples revealed a whitish, fibrous area with a rubbery consistency. On histological examination, diffuse fibrous tissue, hemosiderin deposition, and chronic inflammation were observed. The first case showed the complete disappearance of the tumor, whereas the second case showed just a small (3 mm), residual nest of neoplastic cells. Conclusions: Although spontaneous regression of breast cancer is a rare event, it is important to know that it might happen. It is also of great importance to try to better explain, over time, its underlying mechanism. This knowledge could help us to further develop cancer prevention methods and predict the clinical course of these kinds of neoplasms.

PD-L1 expression in testicular germ cell tumors undergoing spontaneous regression

“…Balzer and Ulbright found a variable lymphoplasmacytic infiltrate in 37/42 (88.1%) samples of regressed testicular germ cell tumours with the conclusion that the immune reaction could play a role in tumour regression [18]. This theory is supported by the many reported cases of tumour regression which followed after acquired infections and febrile conditions, assuming that it occurred due to a strong immune response triggered by the infection [23,24]. PD-1 (Programmed Cell Death Protein-1, also known as CD279) immune checkpoint membrane receptor is one of the markers of over-activated, i.e.…”

“…Along with melanomas, lymphomas, leukaemias, neuroblastomas and renal cell carcinomas, testicular germ cell tumours represent tumours in which spontaneous regression occurs most often, but it has been described in all tumour types [22,23]. Several theories have been proposed about the mechanisms of spontaneous regression, among which the most attention is given to an intense immune response and ischaemia as a result of hypoperfusion and high metabolic demands of the tumour tissue [23][24][25][26]. Historical examples of tumour regression following acquired infection highlight the importance of the inflammatory response in limiting tumour progression [23][27] Recent research on humanized mouse models confirms the active role of CD8+ and CD4+ lymphocytes in the spontaneous regression of allogeneic B cell lymphoma [28].…”

Spontaneous Tumor Regression and Reversion: Insights and Associations with Reduced Dietary Phosphate

“…Dr. Cole also pointed out the difficulty of accurately estimating the incidence rate of spontaneous cancer regression, which he suggested is far more frequent than 1 out of 80,000 to 100,000 cancer patients. Spontaneous regression has most often been documented for lymphomas, neuroblastomas, melanomas, renal cell carcinomas, and testicular malignancies, and less often for breast cancer and lung cancer [ 3 ]. However, Papac noted the reason that the spontaneous regression of breast cancer is rarely reported is because it is so commonly treated [ 21 ].…”

“…A handful of recently published papers on the spontaneous regression and reversion of tumors has revived interest in unexplained tumor disappearance, a historical phenomenon observed over many centuries in plants, animals, and humans [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. The spontaneous regression of cancer in humans was defined in 1956 by Dr. Warren H. Cole and Dr. Tilden C. Everson as “the partial or complete disappearance of a malignant tumor in the absence of all treatment, or in the presence of therapy which is considered inadequate to exert a significant influence on neoplastic disease” [ 9 ].…”