|LETTER TO EDITOR
|Year : 2013 | Volume
| Issue : 2 | Page : 136-137
Spontaneous tumor regressions and intratumoral immunity in cancer research
Manigreeva Krishnatreya, Amal C Kataki, Rajjyoti Das
Department of Cancer Registry, Division of cancer Epidemiology, Dr. B Borooah Cancer Institute, A K Azad Road, Gopinath Nagar, Guwahati, Assam, India
|Date of Web Publication||16-Sep-2013|
Room no: 5, OPD Block, Dr. B Borooah Cancer Institute, A K Azad Road, Gopinath Nagar Guwahati - 781 016, Assam
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Krishnatreya M, Kataki AC, Das R. Spontaneous tumor regressions and intratumoral immunity in cancer research. Muller J Med Sci Res 2013;4:136-7
|How to cite this URL:|
Krishnatreya M, Kataki AC, Das R. Spontaneous tumor regressions and intratumoral immunity in cancer research. Muller J Med Sci Res [serial online] 2013 [cited 2022 May 26];4:136-7. Available from: https://www.mjmsr.net/text.asp?2013/4/2/136/118251
Spontaneous tumor regression (STR) is one of the most fascinating phenomena observed in medical sciences. The first classic monograph on STR was laid by T C Everson and W H Cole in 1966. In the recent past STRs have been reported in the literature. , The authors would like to mention about two cases of STR in the head and neck region upon their limited experience.
A 58-year-old male patient with squamous carcinoma on the medial wall of the right pyriform sinus [Figure 1] with secondary neck node (T2N1M0, stage III), who defaulted soon after the diagnosis, reported to our institute after about a year. On examination, the pyriform sinus was normal with no signs of growth or ulcer [Figure 2], though the secondary neck node had considerably increased in its size after 1 year (T0N3M, stage IV). The patient was advised for external beam radiotherapy, but he declined it and defaulted again.
|Figure 1: The growth (black arrow) in the medial wall of right pyriform sinus with the biopsy forceps|
Click here to view
A 45-year-old male patient with squamous carcinoma of the left buccal mucosa (1.5 cm × 1 cm ulcer-proliferative growths, T1N0M0 lesion, stage I) presented at our institute. The patient was advised for the wide local excision of the growth. However the patient declined surgery. To our utter surprise the patient reported after 4 months without any signs of malignancy in the left buccal mucosa [Figure 3]. Both these patient biopsies were done outside our institute and there was no history of any known cancer-directed treatment found in both these patients elsewhere as well.
Various mechanisms have been postulated for STR like the immunological mechanism, hormonal, induction of differentiation, psychological, apoptosis, tumor necrosis, and epigenetic mechanisms.  The authors would like to emphasize on the role of immunity as a defense mechanism against cancer. The intratumoral immune reaction in the evolution of cancer has been noted.  In the process of carcinogenesis, the tumor cells adapt to various inhibitory stimuli within our body and the last barrier protecting against cancer is the activity of the immune system.  The hypothesis that cancer development is strictly controlled by the host's immune system has been documented and the role of host-immune reaction is important for the better understanding of cancer evolution.  Recent studies demonstrated the presence of CD8 (+) plus CD45RO (+) cells in specific tumor regions as a predictor of tumor recurrence, survival, and also for classification of cancers for prognosis over the conventional AJCC/UICC classifications. , These studies have stressed the role of local immunity in cancer control and raises the question, why in only some patients there is such an intratumoral immune activity, whereas in patients with cancer recurrence fails to demonstrate this intratumoral immunity. Altruistic behavior of cancer stem cells for their survival in adverse hypoxic conditions in a tumor microenvironment is known recently and whether the check by the local immune mechanism fails in recurrences or otherwise because of the these behavior against local intratumoral immune reaction remains to be answered. 
Currently there are no standardized guidelines for the consequent management of patients with STR other than further offering the standard modalities of treatment. Scope for the research on the intratumoral immune mechanism of patients with cancer should be explored in the context of STR and it will open a new dimension in the field of cancer research.
| References|| |
|1.||Kalialis LV, Drzewiecki KT, Klyver H. Spontaneous regression of metastases from melanoma: Review of the literature. Melanoma Res 2009;19:275-82. |
|2.||Bir AS, Fora AA, Levea C, Fakih MG. Spontaneous regression of colorectal cancer metastatic to retroperitoneal lymph nodes. Anticancer Res 2009;29:465-8. |
|3.||Papac RJ. Spontaneous regression of cancer: Possible mechanisms. In vivo 1998;12:571-8. |
|4.||Bindea G, Mlecnik B, Fridman WH, Pagès F, Galon J. Natural immunity to cancer in humans. Curr Opin Immunol 2010;22:215-22. |
|5.||Jakóbisiak M, Lasek W, Go³ab C. Natural mechanisms protecting against cancer. Immunol Lett 2003;91:103-22. |
|6.||Mlecnik B, Bindea G, Pagès F, Galon J. Tumor immunosurveillance in human cancers. Cancer Metastasis Rev 2011;30:5-12. |
|7.||Pages F, Kirilovsky A, Mlecnik B, Asslaber M, Tosolini M, Bindea G, et al. In situ cytotoxic and memory T cells predict outcome in patients with early-stage colorectal cancer. J Clin Oncol 2009;27:5944-1. |
|8.||Galon J, Pages F, Marincolo FM, Thurin M, Trinchieri G, Fox BA, et al. The immune score as a new possible approach for the classification of cancer. J Transl Med [serial online] 2012. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3269368/. [Last accessed on 2013 Apr 9]. |
|9.||Das B, Bayat-Mokhtari R, Tsui M, Lofti S, Tsuchida R, Felsher DW, et al. HIF-2á suppresses p53 to enhance the stemness and regenerative potential of human embryonic stem cells. Stem Cells 2012;30:1685-95. |
[Figure 1], [Figure 2], [Figure 3]