Evaluation of the pathologic response to neoadjuvant treatment in rectal cancer. Experience at the Instituto de Cancerología de Medellín (Colombia, 2011-2017). / Evaluación de la respuesta patológica al tratamiento neoadyuvante en cáncer de recto. Experiencia del Instituto de Cancerología de Medellín (Colombia, 2011-2017).

INTRODUCTION AND AIMS: Neoadjuvant therapy in rectal cancer is associated with a decrease in tumor size and is the therapeutic indication for patients with T3 or T4 tumors or lymph node involvement. Our aim was to describe the frequency of pathologic response and the survival rate in patients that underwent neoadjuvant therapy for rectal cancer. MATERIALS AND METHODS: A retrospective follow-up study with a survival analysis was conducted. Patients with locally advanced rectal cancer that received neoadjuvant treatment and were operated on at the Instituto de Cancerología Las Américas (Medellín, Colombia) were analyzed. Survival was calculated using the Kaplan-Meier method. RESULTS: A total of 152 patients were included. Mean patient age was 59 years (12.8 SD), 53.9% were men, and 58.6% of the patients were diagnosed with stage IIIB disease. The pathologic complete response (pCR) was achieved in 17% of the patients. A total of 146 (96.1%) patients received the chemoradiotherapy protocol. Fifty-two (34.2%) patients developed metastasis and/or relapse, and one (3.8%) of those patients had presented with pCR. The median follow-up period was 33 months (Q1-Q3: 20-45), with an overall survival rate of 79.5% (95% CI 70.9-85.8). The 5-year survival rate for the patients that had pCR was 80% (95% CI 20.3-96.9). CONCLUSIONS: The frequency of pCR was similar to that in other published studies and disease recurrence was lower, compared with patients with no response. The 5-year survival rate in patients with pCR was high, albeit lower than that reported in other studies.

Colorectal cancer survival at an oncologic center in Colombia. A historic cohort study. / Supervivencia de cáncer colorrectal en un centro oncológico de Colombia. Estudio de cohorte histórica.

INTRODUCTION AND AIMS: In Colombia, cancer of the colon is the third most frequent cancer in relation to incidence and mortality. Five-year survival depends on stage at diagnosis, albeit that rate is not known for the country. The aim of the present study was to characterize the overall survival and disease-free survival rates in an adult population with colorectal cancer treated at an oncology center in Medellín, Colombia. MATERIALS AND METHODS: A retrospective cohort study was conducted. The case records of patients with a histologic diagnosis of colorectal cancer, seen within the time frame of 2011 and 2015, were reviewed. The overall survival and disease-free survival curves were calculated using the Kaplan-Meier method. RESULTS: A total of 824 (54.9%) patients with cancer of the colon and 676 (45.1%) with cancer of the rectum were treated. Mean patient age was 63.3 years, female sex predominated (56.3%), and 98.1% of the tumors were adenocarcinomas. The majority of the lesions were stage iii (31.9% in the colon and 35.5% in the rectum) at the time of diagnosis. Surgery was the most frequent treatment in the colon (85.2%) and radiotherapy was the most frequent in the rectum (75.4%). Overall survival at the median follow-up (27.3 months) was 66.7% for cancer of the colon and 63.9% for cancer of the rectum. Disease-free survival at the median follow-up (18.6 months in colon and 14.9 in rectum) was 72.5 and 68.9%, respectively. CONCLUSIONS: The clinical characteristics and treatment of patients were similar to those found in other studies. Two-year survival was higher than in other Colombian reports and 5-year survival was lower than that observed in developed countries.

A multi-gene panel study in hereditary breast and ovarian cancer in Colombia.

Germline mutations in BRCA1 and BRCA2 account for approximately 50% of inherited breast and ovarian cancers. Three founder mutations in BRCA1/2 have been reported in Colombia, but the pattern of mutations in other cancer susceptibility genes is unknown. This study describes the frequency and type of germline mutations in hereditary breast and/or ovarian cancer genes in a referral cancer center in Colombia. Eighty-five women referred to the oncogenetics unit of the Instituto de Cancerologia Las Americas in Medellin (Colombia), meeting testing criteria for hereditary breast and ovarian cancer syndrome (NCCN 2015), who had germline testing with a commercial 25-gene hereditary cancer panel, were included in the analysis. Nineteen patients (22.4%) carried a deleterious germline mutation in a cancer susceptibility gene: BRCA1 (7), BRCA2 (8), PALB2 (1), ATM (1), MSH2 (1) and PMS2 (1). The frequency of mutations in BRCA1/2 was 17.6%. One BRCA2 mutation (c.9246dupG) was recurrent in five non-related individuals and is not previously reported in the country. Seventeen mutation-carriers had a diagnosis of breast cancer (median age of diagnosis of 36 years) and two of ovarian cancer. All BRCA1 mutation-carriers with breast cancer had triple negative tumors (median age of diagnosis of 31 years). Variants of unknown significance were reported in 35% of test results. This is the first report of a multi-gene study for hereditary breast and/or ovarian cancer in a Latin American country. We found a high frequency and a wide spectrum of germline mutations in cancer susceptibility genes in Colombian patients, some of which were not previously reported in the country. We observed a very low frequency of known Colombian founder BRCA1/2 mutations (1.2%) and we found mutations in other genes such as PALB2, ATM, MSH2 and PMS2. Our results highlight the importance of performing multi-gene panel testing, including comprehensive BRCA1/2 analysis (full gene sequencing and large rearrangement analysis), in high-risk breast and/or ovarian cancer patients in Colombia.

Methyl aminolevulinate plus red light vs. placebo plus red light in the treatment of photodamaged facial skin: histopathological findings.

BACKGROUND: Improvement in the morphological appearance of collagen and elastic fibres has been reported after the use of trichloroacetic acid, dermabrasion and laser therapy, but the histopathological changes occurring after photodynamic therapy are less understood. AIM: To assess the histological changes that occur after methyl aminolevulinate (MAL) plus red-light therapy for facial photodamage. METHODS: This was a prospective, double-blind, double-arm, randomized, placebo-controlled trial of MAL plus red light in patients with facial photodamage. A 3-mm punch biopsy was taken from each side of the face before randomization and start of therapy. A dermatopathologist blinded to the treatment assessed epidermal and dermal layer thickness, perivascular inflammation, solar elastosis, perifollicular fibrosis, telangiectasias, number of elastic and collagen fibres, and grade of reticular degeneration. RESULTS: In total, 65 women were initially screened for eligibility, but skin samples from only 38 of these were analysed. The change in dermal thickness from baseline to postintervention was significant (P < 0.01, Wilcoxon signed rank test). Although there was a trend for the epidermis to be thinner after MAL plus red light vs. placebo plus red light (46.25 µm vs. 55.50 µm, respectively), the difference was not significant (P = 0.64, Mann-Whitney U-test). Similarly, the changes in dermal thickness obtained with the two treatments were not significant (P = 0.99, Mann-Whitney test). Histological improvement was seen using stains for collagen, elastic tissue, and perifollicular fibrosis after MAL plus red light therapy. DISCUSSION: Dermal thickness increased after the use of MAL plus red light, and there was improvement in collagen, elastic tissue and perifollicular fibrosis. Although these differences were not significant, most of the histopathological features examined in our study improved after treatment with MAL plus red light. The lack of significance might be due either to the low power of this study or to the failure of our scoring method to detect significant histopathological differences.

A prospective split-face double-blind randomized placebo-controlled trial to assess the efficacy of methyl aminolevulinate + red-light in patients with facial photodamage.

BACKGROUND: To date, there is no gold standard therapy for skin photoageing. In the last decade, laser technologies have offered great promise among skin-rejuvenation therapies; however, both non-ablative and ablative fractional resurfacing modalities have their own benefits and drawbacks. More recently, open-label studies and few controlled trials have suggested that photodynamic therapy may have therapeutic potential in photodamage. OBJECTIVE: To assess the efficacy of methyl aminolevulinate + red-light on facial photodamage in a double-blind split-face randomized placebo-controlled trial. METHODS: Subjects had initially two split-face treatments 2-3 weeks apart in which half of the face was treated with MAL + red-light compared with placebo + red-light. Primary outcome was the assessment of global photodamage 1 month after session 2. Secondary outcomes included the assessment of fine lines, mottled pigmentation, tactile roughness, sallowness, erythema and telangiectasia 1 month after session 2, according to severity scores rated as failure, improvement or success. RESULTS: Based on the intention-to-treat analysis, a total of 48 patients (96 split-faces) were included. Facial global photodamage success or improvement had occurred in 94 split-faces and in no split-faces receiving placebo (RR: 0.02; 95% confidence interval, 0.0-0.14; P = 0.0000). One patient had an adverse event that led to the discontinuation of the therapy after session 1. CONCLUSIONS: Methyl aminolevulinate + red-light demonstrated significantly superior efficacy in global facial photodamage compared with placebo. This therapy was also useful for all other specific secondary outcomes, except for telangiectasia. Overall, MAL + red-light sessions were well tolerated and resulted in high/total patient satisfaction in the majority of subjects (80.4%).

An integrated malaria control program with community participation on the Pacific Coast of Colombia.

The study focuses on integrated malaria control in 23 communities on the Pacific Coast of Colombia, with several elements of an ecosystem approach to human health, including malaria-related sociopolitical, ecological, and economic factors. The program fostered community participation. The program presented here had 2 components: implementation and research. The first was conducted in 23 communities, 21 of which lacked adequate health services in terms of education, community participation, prompt diagnosis and complete treatment, and vector control. Research focused on specific vector control measures and the current national health services decentralization process. The project: 1) created a malaria prevention culture in the community; 2) avoided deaths from malaria (no fatal cases in the 3-year period, compared to 5-8 deaths a year previously); 3) avoided cases of cerebral malaria (no cases, as compared to 90-110 per year previously); 4) reduced malaria incidence by 45.36%; 5) decreased length of sick leave from 7.52 to 3.7 days; 6) established a permanent network of microscope technicians and 2-way radio communications; 7) integrated work by local, regional, and outside institutions; 8) demonstrated efficacy of insecticide-impregnated bednets to reduce malaria transmission.

Humoral immune response to the anti-malaria vaccine SPf66 in the Colombian Atrato River region.

The immunogenicity of anti-malaria synthetic vaccine SPf66 was tested in a region of the Colombian middle Atrato river. The specific serum antibodies against SPf66 were quantified in vaccinees and placebo injected controls for a two-years period post-immunization. The frequency of individuals showing seroconversion of anti-SPf66 antibodies three months after completion of the immunization schedule was higher in vaccinees than in controls (52.7% and 25.5%, respectively, p < 0.01). However, an over than four-fold increase of the specific anti-SPf66 antibody titers was observed only in 1.4% of vaccinees and 0.2% of the controls (p < 0.01). The anti-SPf66 antibody titers augmented in vaccinees from first dose application to three months after the third dose, continuously decreasing thereafter to reach below baseline values two years after completion of the immunization schedule. The results show that SPf66 has very low immunogenicity and induces a short term humoral immune response (six months).

Humoral immune response to the anti-malaria vaccine SPf66 in the Colombian Atrato river region

The immunogenicity of anti-malaria synthetic vaccine SPf66 was tested in a region of the Colombian middle Atrato river. The specific serum antibodies against SPf66 were quantified in vaccinees and placebo injected controls for a two-years period post-immunization. The frequency of individuals showing seroconversion of anti-SPf66 antibodies three months after completion of the immunization schedule was higher in vaccinees than in controls (52.7 per cent and 25.5 per cent, respectively, p<0.01). However, an over than four-fold increase of the specific anti-SPf66 antibody titers was observed only in 1.4 per cent of vaccinees and 0.2 per cent of the controls (p<0.01). The anti-SPf66 antibody titers augmented in vaccinees from first dose application to three months after the thrid dose, continuously decreasing thereafter to reach below baseline values two years after completion of the immunization schedule. The results show that SPf66 has very low immunogenicity and induces a short term humoral immune response (six months).