Background: Several studies have described a worse prognosis for right-sided colon cancer compared to left-sided. However, results are conflicting for different tumor stages. The aim of the study was to compare survival and patterns of recurrence following resection of liver metastases from right-sided colon cancer (RS-LM) versus left-sided (LS-LM). Patients and Methods: Patients undergoing first resection for colon cancer LM between 2000 and 2017 were analyzed. Tumors of the cecum, ascending, and transverse colon were defined as rightsided; tumors of the sigmoid flexure, descending, and sigmoid colon were defined as left-sided. Rectal cancer, multiple primaries and unknown location were excluded. Results: Out of 995 patients, 686 fulfilled inclusion criteria (RS-LM=322, LS-LM=364). RS colon cancer had higher prevalence of metastatic lymph nodes (67.4% vs. 57.1%; P =0.008). RS-LM were more often mucinous (16.8% vs. 8.5%, P=0.001) and poorly differentiated (58.3% vs. 48.9%, P=0.014). After a median follow-up of 81 months, 451 (65.7%) patients experienced recurrence (RS-LM 49.2% vs. LS-LM 50.8%). In RS-LM group, recurrence was more often encephalic (2.3% vs. 0%; P= 0.029) and at multiple sites (34.2% vs. 23.5%; P=0.012). The rate of re-resection was significantly lower in RS-LM patients (27.9% vs. 37.5%; P = 0.024), also considering only liver recurrences (22.9% vs. 37.6%, p=0.012). Multivariate analysis showed RS-LM to have lower rates of five-year overall (35.8% vs. 51.2%, P=0.002) and disease-free survival (26% vs. 43.6%, P=0.002). Conclusions: RS-LM were more often mucinous and poorly differentiated compared with LS. RS-LM is associated with worse survival and aggressive rarely re-resectable recurrences.

Purpose Two months after its first COVID-19 case, Italy counted more than 190,000 confirmed positive cases. From the beginning of April 2020, the nationwide lockdown started to show early effects by reducing the total cumulative incidence reached by the epidemic wave. Here we provide the reproduction number estimation both in space and in time from February 24 to April 24, 2020 over 2 months into the epidemic. Methods The aim of the present work was to provide a systematical mapping of the SARS-CoV-2 transmission dynamics spread to all regions of Italy. To do so, we estimated the basic reproduction number (R 0 ), by using the maximum likelihood estimation method in the early stage of the epidemic. In addition, we determined time evolution of this parameter across the 2 months of the observational period. Finally, we linked R t , with two indices, the first representing the number of contagious people and the latter the density of susceptibiltiy to infection of people in a region as recorded on April 24, 2020. Results Our estimates suggest a basic reproduction number averaged over all the regions of 3.29. Based on the SARS-CoV-2 transmission dynamics reported here, we gave a quantitative evaluation of the efficiency of the government measures to lower the reproduction number below 1 (control regime). We estimated that the worst-hit regions in Italy reached the control regime level (R t < 1) in about a month. Conclusion Our work was carried out in the period between April and July,2020. We found that the mean value of time to reach the control regime across the whole country was about 31 days from February 24, 2020. Moreover, we highlighted the interplay between the reproduction number and two epidemiological/demographic indices to evaluate the "state of activity" of the epidemic, potentially helping in challenging decisions to continue, ease, or tighten restrictions.

After two months from the first case in COVID-19 outbreak, Italy counts more than 190,000 confirmed positive cases. From the beginning of April 2020, the nationwide lockdown started to show early effects by reducing the total cumulative incidence reached by the epidemic wave. This allows the government to program the measures to loosen lockdown restrictions for the so called "Phase 2". Here we provided the reproduction number estimation both in space and in time from February 24 th to April 24 th , 2020 across two months into the epidemic. Our estimates suggest basic reproduction number averaged over all the regions of 3.29, confirming that epidemiological figures of the SARS-CoV-2 epidemic in Italy are higher than those observed at the early stage of Wuhan (China) outbreak. Based on the SARS-CoV-2 transmission dynamics reported here, we gave a quantitative evaluation of the efficiency of the government measures to low the reproduction number under the unity (control regime). We estimated that among the worst hit regions in Italy, Lombardy reached the control regime on March 22 nd followed by Emilia-Romagna (March 23 th ), Veneto (March 25 th ) and Piemonte (March 26 th ). Overall, we found that the mean value of time to reach the control regime in all the country is about 31 days from the February 24 th and about 14 days from the first day of nationwide lockdown (March 12 th ). Finally, we highlighted the interplay between the reproduction number and two demographic indices in order to probe the "state of activity" of the epidemic for each Italian region in the control regime. We believe that this approach can provide a tool in the management of "Phase 2", potentially helping in challenging decision to continue, ease or tighten up restrictions.