Has the COVID-19 pandemic changed the clinical picture and tumour stage at the time of presentation of patients with colorectal cancer? A retrospective cohort study

Introduction

Treatment of patients with Coronavirus Disease 2019 (COVID-19) has affected the management of patients with colorectal cancer (CRC). The aim of this study was to compare the diagnosis delay, symptoms, and stage of patients with CRC during the pandemic with a control cohort.

Material and methods

Patients referred to the CRC multidisciplinary team between September 2019 and January 2020 (cohort 1, control group) were compared with those who presented between September 2020 and March 2021 (cohort 2, pandemic group).

Results

389 patients were included, 169 in cohort 1 and 220 in cohort 2. No differences were observed in the main characteristics of the patients. CRC screening and anaemia were the most common causes leading to the diagnosis of the tumour in cohort 1 and 2, respectively (p < 0.001). Diagnostic and therapeutic delay was longer in cohort 2 [6.4 (95% CI 5.8-6.9) vs. 4.8 (95% CI 4.3-5.3) months, p < 0.001]. More patients required non-elective treatment in the pandemic cohort (15.5% vs. 9.5%, p = 0.080). The tumour stage was more advanced in patients in cohort 2 [positive nodes in 52.3% vs. 36.7% (p = 0.002), and metastatic disease in 23.6% vs. 16.6% (p = 0.087)].

Conclusion

CRC patients in the pandemic cohort had a longer diagnostic and therapeutic delay and less patients were diagnosed because of CRC screening. In addition, patients with CRC during the pandemic needed non-elective treatment more frequently than patients in the control cohort, and their tumour stage tended to be more advanced.

Has the COVID-19 pandemic changed the clinical picture and tumour stage at the time of presentation of patients with colorectal cancer? A retrospective cohort study

INTRODUCTION

Treatment of patients with Coronavirus Disease 2019 (COVID-19) has affected the management of patients with colorectal cancer (CRC). The aim of this study was to compare the diagnosis delay, symptoms, and stage of patients with CRC during the pandemic with a control cohort.

MATERIAL AND METHODS

Patients referred to the CRC multidisciplinary team between September 2019 and January 2020 (cohort 1, control group) were compared with those who presented between September 2020 and March 2021 (cohort 2, pandemic group).

RESULTS

389 patients were included, 169 in cohort 1 and 220 in cohort 2. No differences were observed in the main characteristics of the patients. CRC screening and anaemia were the most common causes leading to the diagnosis of the tumour in cohort 1 and 2, respectively (p<0.001). Diagnostic and therapeutic delay was longer in cohort 2 [6.4 (95% CI 5.8-6.9) vs. 4.8 (95% CI 4.3-5.3) months, p<0.001]. More patients required non-elective treatment in the pandemic cohort (15.5% vs. 9.5%, p=0.080). The tumour stage was more advanced in patients in cohort 2 [positive nodes in 52.3% vs. 36.7% (p=0.002), and metastatic disease in 23.6% vs. 16.6% (p=0.087)].

CONCLUSION

CRC patients in the pandemic cohort had a longer diagnostic and therapeutic delay and less patients were diagnosed because of CRC screening. In addition, patients with CRC during the pandemic needed non-elective treatment more frequently than patients in the control cohort, and their tumour stage tended to be more advanced.

Detection of a t(8;21)(q22;q22) in a case of M5 acute monoblastic leukemia

Although the translocation (8;21) is the single most common structural rearrangement reported in acute myeloblastic leukemia (AML), it is rarely seen in AML FAB type M5. We describe a case of a 51-year-old male with a diagnosis of acute monoblastic leukemia (AML M5b with hemophagocytic component) whose karyotype showed at (8;21)(q22;22). To our knowledge, this is the first report of this translocation in an AML M5b. The t(8;21) has been associated with a good prognosis, but our patient suffered a fast and fatal evolution.

Evaluation of a pooling method for routine anti-HCV screening of blood donors to lower the cost burden on blood banks in countries under development

A pooling system was developed for use in anti-HCV screening of voluntary blood donors at the local Central American Red Cross blood banks, in Nicaragua, El Salvador and Honduras. The commercially available second generation anti-HCV screening kit from Abbott Laboratories (North Chicago, IL) was used with a modification in the initial serum dilution procedure. Pools of five sera were selected for routine screening, based on comparative studies of individual samples and of pools with different sample sizes. During the years 1993 and 1994 a total of 89, 148 voluntary blood donors were screened and a positive prevalence rate of 0.35% was established. Of the initially positive samples, 54% confirmed positive, 30% were indeterminate and 16% were negative using the Abbott Matrix test. Significant differences of positive screening prevalence rates were found in the three countries, with average values of 0.50%, 0.23% and 0.08%, respectively, in Nicaragua, El Salvador and Honduras. These initially positive samples also showed a different confirmatory pattern with a positive rate of 64% in Nicaragua, in contrast to 20% in El Salvador. Only a few samples were available for RT-PCR amplification of HCV-RNA; however, this highly sensitive method did not appear to be more helpful than serology in confirming the HCV donor status. Overall, the data obtained indicate a fluctuation of HCV prevalence in voluntary blood donors among the three Central American countries. Further, differences were found in the percentages of initially screened positives and confirmation patterns. This information appears useful for establishing criteria in future screening policies. Thus, we suggest that the use of pooling for anti-HCV screening is beneficial in countries under development, since there are potential cost savings, as well as benefits in establishment of initial prevalence rates.

Microcinematographic study on the effect of methotrexate upon mouse mammary tumor cells (MMT cell line)

The effect of methotrexate (amethopterin) upon the MMT cell line was studied by time-lapse microcinematography, the plasma levels obtained after systemic administration of maximum tolerated doses of the drug in man being simulated in vitro. Cells in the logarithmic growth phase (large growth fraction population) were widely affected, although enough drug-resistant cells remained to regenerate the cell colony. Cells in the preconfluent growth phase (small growth fraction population) were less effected, because many cells were arrested at the GO-hase, outside the cell cycle. A drug-resistant colony always developed, making the drug therapy useless. The experiments showed that rescue treatment with leucovorin (citrovorum factor of folinic acid) was not effective either, because, at least on our experimental conditions, recovery of the mitotic activity was more rapid and the number of degenerating cells smaller with rescur treatment than with the conventional treatment. The results also suggested a new mechanism of methotrexate action in addition to the classic one of folic acid inhibition, which might consist in the inhibition of the production of formyl-methionyl-tRNA, part of the initiation complex in protein biosynthesis.