Paweł Jarmocik

Heteroplasmic substitutions in the entire mitochondrial genomes of human colon cells detected by ultra-deep 454 sequencing

Mitochondrial DNA (mtDNA) heteroplasmy has been widely described from clinical, evolutionary and analytical points of view. Historically, the majority of studies have been based on Sanger sequencing. However, next-generation sequencing technologies are now being used for heteroplasmy analysis. Ultra-deep sequencing approaches provide increased sensitivity for detecting minority variants. However, a phylogenetic a posteriori analysis revealed that most of the next-generation sequencing data published to date suffers from shortcomings. Because implementation of new technologies in clinical, population, or forensic studies requires proper verification, in this paper we present a direct comparison of ultra-deep 454 and Sanger sequencing for the detection of heteroplasmy in complete mitochondrial genomes of normal colon cells. The spectrum of heteroplasmic mutations is discussed against the background of mitochondrial DNA variability in human populations.

Knowledge of symptoms and diagnostic possibilities of cancer diseases

Introduction The aim of the present study was to analyse patients’ knowledge in the field of neoplastic prophylaxis. Material and methods The research was carried out between 2007 and 2008 in the Provincial Hospital in Bydgoszcz (i.e. general surgery, gynaecology and obstetrics, urology, breast surgery and thoracic surgery). Altogether 300 patients (of whom 250 were hospitalized) as well as 50 healthy subjects forming the control group were invited to participate in the study. A proprietary questionnaire containing eight multiple choice and another twelve open-ended questions was used for the purpose of the study. Results Prostate and lung cancer patients were more aware of their diseases compared to the control group, but the differences were not significant (p = 0.85 and p = 0.53 respectively). In the field of screening the patients’ knowledge, it was significantly higher in breast cancer subjects (p = 0.0008) while there was no difference compared to the control group in the remaining groups of cancer patients (i.e. colorectal, prostate or uterus cancer). Those most aware of their condition were patients from small towns (below 50,000), while subjects living in villages were the least aware. Conclusions Patients showed the greatest amount of knowledge regarding breast cancer and the least amount regarding prostate cancer. Oncological awareness in cancer patients was found to be related to variables such as education, age and residence. No difference was found between patients and controls, comparing their knowledge of disease symptoms as well as screening possibilities.

Usefulness of CEA Concentration Measurement and Classic Colonoscopy in Follow-Up After Radical Treatment of Colorectal Cancer

UNLABELLED There is always a certain rate of recurrence after radical treatment for cancer and to get on it an early detection of disease set back is crucial. MATERIAL AND METHODS Medical data of patients operated on for primarily detected colorectal cancer in years 1993-2002 was retrospectively reviewed. Usefulness of follow-up means such as physical examination, or CEA and endoscopic surveillance was analyzed. All mentioned above were applied to scheduled follow-up (in 3, 6 and 12 month intervals following an operation and annually after that by the year 5). RESULTS Complete and reliable data was obtained from 340 out of 502 follow-up intended subjects (67.7%). Elevated CEA was the most frequent predictor of recurrence within non-symptomatic subjects meeting follow-up appointments (60%). The cancer set back diagnosed by means of either physical or endoscopic examinations was the case only in one out of five patients (20.75% and 18.87% respectively). Clinical onset of recurrence making patients meet an unscheduled appointment was found increasing relative risk of nothing-but-palliative option either for them with local set back, or meta-static spread. Relative risk of onset of meta-chronous colonic cancer was significantly higher in patients being affected by synchronous advanced adenoma at time of surgery compared to those with one-fold changes. CONCLUSIONS CEA scheduled follow-up after treatment for colorectal cancer CRC seems adequate to provide a good outcome of treatment for recurrent tumors. CRC patients presenting with synchronous advanced adenomas at time of surgery are probably to be under more intensive endoscopic surveillance.

Colorectal cancer with intestinal perforation – a retrospective analysis of treatment outcomes

Aim of the study Colorectal cancer (CRC) is one of the leading cause of death in European population. It progresses without any symptoms in the early stages or those clinical symptoms are very discrete. The aim of this study was a retrospective analysis of treatment outcomes in patients with colorectal cancer complicated with intestinal perforation. Material and methods A retrospective analysis of patients urgently operated upon in our Division of General Surgery, because of large intestine perforation, from February 1993 to February 2013 has been made. Results were compared with a group of patients undergoing the elective surgery for colorectal cancer in the same time and Division. Results Intestinal perforation occurred more often in males (6.52% vs. 6.03%), patients with mucous component in histopathological examination (9.09% vs. 6.01%) and with clinicaly advanced CRC. Patients treated because of perforation had a five-fold higher 30 day mortality rate (9.09% vs. 1.83%), however long-term survival did not differ significantly in both groups. After resectional surgery in 874 patients an intestinal anastomosis was made. Anastomotic leakage was present in 23 (2.6%) patients. This complication occurred six-fold more frequently in a group of patients operated upon because of intestinal perforation (12.20% vs. 2.16%). Conclusions In patients with CRC complicated with perforation of the colon in a 30-day observation significantly higher rate of complications and mortality was shown, whereas there was no difference in distant survival rates.

Characteristics and results of treatment of patients treated surgically with colorectal cancer in old and senile age

Colorectal cancer (CC) in Poland is the type of cancer with the highest dynamics of disease growth and is epidemiologically related to age. The analysis involved 353 patients operated on due to CC in senile and old age and compared with younger patients. It was found that people at this age are more often diagnosed with CC They were more often women, the patients did not differ in the stage of cancer, while they were significantly more often qualified for surgery due to urgent indications. In patients with colonic cancer, the resectability and radicality of the procedures in comparison with patients with rectal cancer was significantly higher, while there were more complications and deaths in the 30-day follow-up in this group. The overall survival in senile and old age was significantly worse. In the first year of follow-up after surgical treatment of patients in this group, complications and deaths were more frequently observed. However, in patients who survived 12 months after the operation, the overall survival rate did not significantly differ.

Mitogenomic differences between the normal and tumor cells of colorectal cancer patients

So far, a reliable spectrum of mitochondrial DNA mutations in colorectal cancer cells is still unknown, and neither is their significance in carcinogenesis. Indeed, it remains debatable whether mtDNA mutations are “drivers” or “passengers” of colorectal carcinogenesis. Thus, we analyzed 200 mitogenomes from normal and cancer tissues of 100 colorectal cancer patients. Minority variant mutations were detected at the 1% level. We showed that somatic mutations frequently occur in colorectal cancer cells (75%) and are randomly distributed across the mitochondrial genome. Mutational signatures of somatic mitogenome mutations suggest that they might arise through nucleotide deamination due to oxidative stress. The majority of somatic mutations localized within the coding region (in positions not known from the human phylogeny) and was potentially pathogenic to cell metabolism. Further analysis suggested that the relaxation of negative selection in the mitogenomes of colorectal cancer cells may allow accumulation of somatic mutations. Thus, a shift in glucose metabolism from oxidative phosphorylation to glycolysis may create advantageous conditions for accumulation of mtDNA mutations. Considering the fact that the presence of somatic mtDNA mutations was not associated with any clinicopathological features, we suggested that mtDNA somatic mutations are “passengers” rather than the cause of colorectal carcinogenesis.

Risk factors for surgical site infections in rectal cancer patients

Introduction. Rectal cancer surgery is associated with high rates of post-operative complications in which the most common are Surgical Site Infections (SSI). Materials and methods. Factors responsible for SSI incidence were retrospectively analysed in rectal cancer patients who had undergone surgery at a single centre for oncology between July 2012 and July 2016. The study end-point was patients’ contracting SSI. Statistical analyses were performed by the ‘Statistica 12’ package consisting of the Pearson’s Chi-squared test (χ 2 ), the Kruskal-Wallis test and the Mann-Whitney U-test (with continuity correction). Qualitative variables were analysed using log-linear analysis. The likelihoods of SSI incidence were compared by using odds ratios within 95% confidence limits. Results. Amongst the 187 patient subjects under observation during their 30 day follow-up, 44 (23.5%) suffered from post-operative complications of which SSI were the most common at 27 (14.4%). In those patients with advanced stage IV cancer, SSI occurred 3-fold more compared to patients with lower stage cancers; respectively 27.3% vs 11.7%, p = 0.021. Multivariate analysis demonstrated that the highest SSI risk was in patients having a low-lying tumour (≤ 5 cm from the anal rim; OR 2.31 (95% CI of 1.15 to 4.62), p = 0.019 and those patients who had undergone Hartmann’s procedure; OR 1.85 (95% CI of 1.04 to 3.31), p = 0.038. Conclusions. Surgical site infections in rectal cancer patients undergoing surgery occur significantly more in those at advanced stage IV rectal cancer where the tumour is low-lying (0–5 cm from the anal rim) and after having undergone the Hartmann’s procedure.

Intestinal stoma in patients with colorectal cancer from the perspective of 20-year period of clinical observation

Introduction Intestinal stoma is a procedure most often performed in patients with colorectal cancer. Aim To identify the percentage of patients with colorectal cancer in which the intestinal stoma was performed. Material and methods We retrospectively analysed 443 patients treated during a 20-year period (1994–2013) due to colorectal cancer, in which the intestinal stoma was made during the first surgical intervention. Results In the second analysed decade, a significant decrease in the percentage of created stomas, definitive stomas in particular, was observed. Stomas were made significantly more often in patients with a tumour located in the rectum, the left half of the colon, and in patients undergoing urgent surgeries. An increased incidence of intestinal stomas was associated with a higher severity of illness and higher proportion of unresectable and non-radical procedures. The definitive stomas were significantly more often made in men and in patients with tumours located in the rectum, whereas temporary stomas were created significantly more often in patients undergoing urgent operations. Conclusions In the last decade (2004–2013) the number of intestinal stomas in patients operated due to colorectal cancer was significantly reduced.

Retrospective analysis of patients with hereditary nonpolyposis colorectal cancer (HNPCC).

We performed a one–center cohort retrospective analysis of 1378 non-selected patients operated for colorectal cancer (CRC) in the years 1994 – 2013. For the purpose of this study we divided patients into three subdivisions reflecting their family history of HNPCC–associated cancers among firstand second-degree relatives. On detailed pedigree analysis of the families we identified 59 patients as being affected with HNPCC (4.28%). Compared with other CRC patients our HNPCC subjects were significantly younger at time of diagnosis (median age 51 years, p < 0.05), were more likely to present with right–sided tumors rather than with rectal ones (p < 0.05). Synchronous tumors were found in 45 CRC patients (3.27%), of whom HNPCC subjects were predominant (8.47 vs. 3.03%, p= 0.02). HNPCC patients were also more likely to receive radical resection surgery compared with other CRC patients (93.22% vs. 86.73%). Patients with HNPCC presented with more favorable staging and more frequent mucinous component on histological examination. Overall survival was statistically longer in HNPCC than in other CRC patients (45 vs. 25 months, p =0.01806). Submitted data and our experience in colorectal surgery made us to support conclusion corroborated by literature evidence and regarding fine distinction between HNPCC and sporadic CRC patients.