The Unkindest Cut: How Wounds Can Trigger Tumor Growth

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Sometimes, even a tiny cut can have serious and unexpected consequences. New research reveals that even a minor flesh wound can cause previously dormant cancer cells to develop into tumors.

The study, published in the Proceedings of the National Academy of Sciences,  focuses on basal cell carcinoma, a variety of skin cancer associated with hair follicle cells. Basal cell carcinoma is the most common type of skin cancer, and while it rarely metastasizes or kills it’s still considered malignant.

Biochemists Sunny Wong and Jeremy Reiter, from the  University of California, San Francisco, wanted to see how tumors develop from cancerous mutations. To do that, they genetically modified mice so that their hair follicle stem cells expressed the human basal cell carcinoma gene. After giving some of the mice a small cut, and leaving others alone, they discovered that tumors only formed on the hurt mice.

When skin is cut, hair-follicle stem cells migrate to the injury. Wong says pre-cancerous cells can lie dormant in the body until a trigger, such as radiation or a build up of mutations, pushes them into forming a tumour. “In this case, wounding got cancerous cells out of their resting phase,” he says. [New Scientist]

Although the experiment was short-term, the implication is that the same processes can play out if cells get damaged over time, and if a wound then rouses the sleeping cancer:

The study suggests that, after DNA in the skin’s stem cells is damaged to create a mutation in an oncogene, the mutated cells might rest for years without causing cancer, and might cause problems only when a wound prompts them to act. [Nature]

Scientists have been investigating this wound-cancer trend for several years now.

Reiter said that over the past 10 years, more and more scientists have begun to think that “cancers are wounds gone awry.” Normally, the hair follicle represses the tumor-generating potential of the stem cells, he said, “but when these cells leave their niche, the reins that are supplied by the [follicle] come off. ” [The Scientist]

For some scientists, this study is an exciting development in the fight against cancer.

The work is “pioneering,” said Ervin Epstein, a cancer researcher at the Children’s Hospital Oakland Research Institute in California, who was not involved in the research. “What could be more important than identifying the cell of origin of the most common of human cancers?” [The Scientist]

But not everyone is convinced of the link between wounds and basal cell carcinoma.

[Critics] say that most basal cell carcinomas do not develop at the sites of injury, so the finding is of limited significance. “This is certainly not a major mechanism underlying basal cell carcinoma formation in humans,” says Sabine Werner, a cell biologist at the Swiss Federal Institute of Technology in Zurich. [Nature]

‘Most,’ though, doesn’t mean all–and when it comes to battling cancer, every little step forward counts.

Narrowband-UVB in Early Stage Cutaneous T-Cell Lymphoma

ISRN Dermatology
Volume 2014, Article ID 951821, 4 pages
http://dx.doi.org/10.1155/2014/951821

Efficacy and Side Effects of Narrowband-UVB in Early Stage Cutaneous T-Cell Lymphoma in Jordanian Patients

Salah A. AbdallatAyman S. AlqaqaaNidal A. Obaidat, and Rameh F. Alnueimi

Department of Dermatology, King Hussein Medical Center, Amman 11941, Jordan

Received 1 November 2013; Accepted 31 December 2013; Published 19 February 2014

Academic Editors: B. Amichai, F. M. Camacho, L. Dourmishev, A. Oakley, and W. Vanscheidt

Copyright © 2014 Salah A. Abdallat et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background. Many studies, on light-skinned patients, suggested narrowband-UVB to be effective and safe for the treatment of early stage cutaneous T-cell lymphoma. Objectives. To evaluate the efficacy and side effects of narrowband-UVB in treatment of early stage cutaneous T-cell lymphoma in patients with skin phototypes III, IV, and V. Methods. A total of 27 patients with the diagnosis of early stage cutaneous T-cell lymphoma were involved in this prospective study. All patients received narrowband-UVB as monotherapy until clearance or a maximum of 42 sessions. Patients with complete clearance were followed for six months or relapse. Rate of clearance, number of sessions, and cumulative narrowband-UVB dose needed to achieve clearance, percentage of patients remaining in remission at 6 months, and side effects were analyzed. Results. Within 5–14 weeks (15–42 sessions), using cumulative narrowband-UVB dose ranging from 17.3 to 48.2 J/cm2, complete remission was achieved in 76.4% of patients. The rest of the patients achieved partial remission. Six months after discontinuation of the treatment, 42.8% of patients with complete remission remained in remission. Transient erythema in 11.1% of patients and mild hyperpigmentation in 14.8% of patients were the only side effects encountered during this study. Conclusion. We conclude that narrowband-UVB phototherapy is safe and effective for the treatment of early stage cutaneous T-cell lymphoma in darker-skinned patients.

1. Introduction

Cutaneous T-cell lymphoma (CTCL) is a group of lymphoproliferative disorders with clonal expansion of T helper cells, or rarely T suppressor/killer cells or NK cells, with localization to the skin. This group is characterized by an increased CD4+ cells: CD4/CD8 > 10, and/or an expansion of T cells with a loss of 1 or more of the normal T-cell antigens (CD2, CD3, and CD5) [1].

Cutaneous T-cell lymphomas are very rare, with a prevalence of 5/1000000 per year [12]. They are classified into a group with indolent clinical behavior, which includes mycosis fungoides (MF) and its variants (62%), and primary cutaneous CD30+ lymphoproliferative disorders (26%) and a group with aggressive clinical behavior (12%) like Sézary syndrome and adult T-cell leukemia/lymphoma [2].

MF, the commonest form of CTCL, presents as patches and plaques over trunk and proximal extremities, without internal involvement. It has a predilection for older adults and male gender [35]. MF is classified into early (stage IA, IB, and IIA) and advanced (stage IIB, III and IV) stages [23].

In early stages, the clinical and pathological presentation are similar to other inflammatory dermatoses, for example, Atopic eczema. Repeated skin biopsies are usually needed to establish the diagnosis [45]. Treatment of early stage MF includes topical agents (corticosteroid, nitrogen mustards, carmustine, and bexarotene) [6], electron beam therapy, and phototherapy including ultraviolet light, excimer laser, and photodynamic therapy [79].

Many studies involving Western populations showed that NB-UVB is effective for early stage MF [78], but there is lack of studies on NB-UVB in early MF in darker-skinned patients. In this study, we analyzed the efficacy and safety of NB-UVB in patients with skin phototypes III, IV, and V having early stage MF.