Rightward shift in colorectal cancer: experience in 1101 patients

BACKGROUND

In the past decades the right colon cancer showed a higher incidence rate than left colon cancer. This trend is known as "proximal shift" or "rightwards shift." We evaluated rightward shift phenomenon in our region.

METHODS

We collected data from 1101 colorectal cancer patients who underwent curative surgery at Parma University Hospital from 01 January 2004 through 01 January 2018. We divided patients into seven subgroups according to the time of surgery to evaluate epidemiological changes through the years of colon cancer.

RESULTS

We found a non-linear rightward shift trend of CRC. The incidence of RCC was the 40% between 2004-2005 and 51% in the biennium 2016-2017 (60% in 2012-2013 and 57% in 2014-2015). The patients with RCC were significantly older than patients with LCC. RCCs have poor differentiated tumors. Metastatic disease showed a similar distribution both in left and right CRCs. Peritoneum was the most common metastasis location from right-sided colon cancer.

CONCLUSIONS

Data suggest the existence of two different tumor entities in CRC between right-sided colon cancer and left-sided colon cancer. The proximal shift may be a reflection of improved screening programs, diagnostic accuracy and population aging. Ethnicity, gender, diet, environment, and socioeconomic status contribute to CRC incidence and prevalence in different regions.

Increased density of M1 receptors in the hippocampus of juvenile rats chronically deprived of NGF

Binding studies were used to assess the changes in affinity and/or number of M1 muscarinic receptors in hippocampi from juvenile rats chronically deprived of NGF. NGF deprivation was obtained by implanting into right ventricle at postnatal day 2 (P2) hybrydoma cells secreting high levels of monoclonal antibodies against NGF (alphaD11). Parenteral myeloma cells (P3U) were used as controls. Competition experiments were used to characterise the [3H]-PNZ binding sites in membrane preparations of hippocampi from rats sacrificed at P15. [3H]-PNZ bound M1 receptors both in P3U and alphaD11 group as shown by displacing potency order of antagonists: TLZ=4-DAMP>PNZ>p-F-HHSiD>MTC. The deprivation of NGF for two weeks significantly increased the number of M1 receptors without changing the Ki values of antagonists with exception of methoctramine which showed an increase in affinity in alphaD11 group. Similar changes in binding parameters were already observed after the first week of anti-NGF treatment. In contrast, a treatment for a week with implant at postnatal day 15 failed to produce any changes in M1 binding parameters. These results provide further physiological evidence for developmentally regulated modulatory role of NGF in the cholinergic function in the hippocampus.