BACKGROUND Natural killer (NK) cells have a spontaneous cytotoxic capacity against tumor cells. These cells represent a small proportion of human colon carcinoma‐infiltrating lymphocytes. Their prognostic significance in these tumors has yet to be determined. METHODS One hundred and fifty‐seven patients who each had a colectomy for large bowel adenocarcinoma were studied. No patient received adjuvant therapy. Immunohistochemical stains were performed for NK cells using the monoclonal antibody CD57. The number of NK cells was counted using a MICRON image analyzer. The total area studied for each tumor was 1 cm2. In this area, 50 intratumoral fields of 0.173 mm2 were selected. The degree of NK infiltration was classified as little (<50 NK cells), moderate (50‐150 NK cells), and extensive (>150 NK cells). The Kaplan‐Meier method was used to obtain survival figures. Multivariate analyses were performed using the Cox regression model. RESULTS At 5 years, patients with little and moderate NK infiltration showed significantly shorter survival rates (overall and disease free survival) than those with extensive infiltration (P < 0.01). Three significant factors affecting survival were selected in a stepwise fashion in increasing order as follows: TNM stage, NK infiltration, and lymphocytic infiltration. Patients with TNM Stage III disease and extensive NK infiltration showed significantly longer survival rates than those with little or moderate infiltration (P < 0.001). In these patients, multivariate analysis using the Cox regression model identified two significant variables: number of involved lymph nodes and NK cell infiltration. CONCLUSIONS In patients with colorectal carcinoma, an extensive intratumoral infiltration of NK cells is associated with a favorable tumor outcome. Intratumoral infiltration of NK cells can be used as a variable with prognostic value, especially in patients with TNM Stage III disease. Cancer 1997; 79:2320‐8. © 1997 American Cancer Society.

Background: The detection of sub-clinical breast lesions has increased with screening mammography. Biopsy techniques can offer precision and agility in its execution, as well as patient comfort. This trial compares radioguided occult lesion localization (ROLL) and wire-guided localization (WL) of breast lesions. We investigate if a procedure at the ambulatorial level (ROLL) could lead to a better aesthetic result and less postoperative pain. In addition, we intend to demonstrate the efficacy of radioguided localization and removal of occult breast lesions using radiopharmaceuticals injected directly into the lesions and correlate radiological and histopathological findings.

SummaryArf/p53 pathway protects the cells against DNA damage induced by acute stress. This characteristic is the responsible for its tumor suppressor activity. Moreover, it regulates the chronic type of stress associated with aging. This is the basis of its anti‐aging activity. Indeed, increased gene dosage of Arf/p53 displays elongated longevity and delayed aging. At a cellular level, it has been recently shown that increased dosage of Arf/p53 delays age‐associated stem cell exhaustion and the subsequent decline in tissue homeostasis and regeneration. However, p53 can also promote aging if constitutively activated. In this context, p53 reduces tissue regeneration, which correlates with premature exhaustion of stem cells. We discuss here the current evidence linking the Arf/p53 pathway to the processes of aging and cancer through stem cell regulation.

Cutaneous melanoma (CM) is responsible for 75% of deaths from malignant skin cancer. The incidence of CM in the southern region of Brazil, particularly in the western region of Santa Catarina, is possibly higher than estimated. In this study, the clinical and epidemiological profile of patients with CM treated in the western region of Santa Catarina was examined. A cross-sectional study was performed with patients diagnosed with CM from January 2002 to December 2009, from 78 counties of the western region of the state of Santa Catarina. Data were collected using a protocol adapted from the Brazilian Melanoma Group and 503 patients were evaluated. The incidence and prevalence of CM found in this region are much higher than those found elsewhere in the country. This fact is most likely due to the phenotypic characteristics of the population and the high incidence of UV radiation in this region due to its location in southern Brazil, as is the case in the countries of Oceania.

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Skin cancer represents a serious public health problem and melanoma is considered the most significant due to its high metastasis capacity. Evasion mechanisms are the main characteristic of these tumor cells to escape of immune response. Extracellular nucleotides and nucleosides play an important role in inflammatory and immune responses. In this study, we analyzed the expression and activity of purinergic system enzymes in platelets and lymphocytes, ATP levels quantification, as well the level of pro and anti-inflammatory interleukins in the serum of 23 patients with surgical melanoma removal (CM group) and 23 control subjects (CT group). Results showed a decrease in ATP, ADP, and AMP hydrolysis and an increase in ATP levels quantification in CM group. The pro-inflammatory cytokines were elevated in CM group when compared to CT group. These results suggest an inflammatory process, even after surgical removal, due to elevated extracellular ATP levels. Besides, CM group displayed an increase in IL-10 levels and an increased in ADA activity in platelets and lymphocytes. Once adenosine and IL-10 are anti-inflammatory molecules, these results indicate a down-regulation of immune system front to malignant process. The alteration in nucleotide and nucleoside hydrolysis reinforces the purinergic systems role in this cancer. Therefore, even after surgical removal, the purinergic system can develop a chronic inflammatory micro-environment that can influence directly on relapse or metastasis.

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