The impact of adjuvant chemotherapy on survival in mucinous and non-mucinous rectal adenocarcinoma patients after TME surgery.

INTRODUCTION: The value of adjuvant chemotherapy for rectal cancer patients is debated and varies in different subgroups. One such subgroup is mucinous adenocarcinoma (MAC), which is more treatment resistant compared to non-mucinous adenocarcinoma (NMAC). To date, mucinous histology is not taken into account when deciding on adjuvant treatment strategy. This is the first study to exclusively include patients with rectal cancer, then separate MAC and NMAC and compare the survival in patients that had or did not have adjuvant chemotherapy. MATERIAL AND METHODS: The study included retrospective register data from 365 Swedish patients with stage II-IV rectal adenocarcinoma, 56 patients with MAC and 309 patients with NMAC. All patients were considered curative, had surgery with total mesorectal excision in 2004-2013, and were followed up until death or 2021. RESULTS: Patients with MAC that had adjuvant chemotherapy had better overall survival (OS, HR 0.42; CI 95%: 0.19-0.93; p = 0.032) and a trend towards better cancer-specific survival (CSS, HR 0.41 CI 95%: 0.17-1.03; p = 0.057) compared to patients without chemotherapy (HR 0.42; CI 95%: 0.19-0.93; p = 0.032). The difference in OS was still significant even after adjusting for sex, age, stage, differentiation, neoadjuvant chemotherapy and preoperative radiotherapy (HR 0.40; CI 95%: 0.17-0.92; p = 0.031). There was no such difference in the NMAC patients except in the stage-by-stage subgroup analyses where patients in stage IV had better survival after adjuvant chemotherapy. CONCLUSIONS: There may be a difference in treatment response to adjuvant chemotherapy between MAC and NMAC patients. Patients with MAC could possibly benefit from adjuvant chemotherapy in stages II-IV. Further studies are however needed to confirm these results.

Simultaneous or staged resection of synchronous colorectal cancer liver metastases: a 13-year institutional follow-up.

BACKGROUND: This study compared postoperative outcomes and survival rates of patients who underwent simultaneous or staged resection for synchronous colorectal cancer liver metastases. METHODS: Between 2005 and 2018, 126 patients were registered prospectively at a university hospital in Sweden, 63 patients who underwent simultaneous resection were matched against 63 patients who underwent staged resection. RESULTS: The length of hospital stay was shorter for the simultaneous resection group, at 11 vs 16 days, p = <0.001. Fewer patients experienced recurrence in the simultaneous resection group 39 vs 50 patients, p = 0.012. There were no significant differences in disease-free survival and overall survival between the groups. Age (hazard ratio [HR] 1.72; 95% CI 1.01-2.94; p = 0.049) and Clavien-Dindo score (HR 2.22; 95% CI 1.06-4.67; p = 0.035) had impact on survival. CONCLUSION: Colorectal cancer with synchronous liver metastases can be resected simultaneously, and enables a shorter treatment time without jeopardizing oncological outcomes.

Mucinous and Non-Mucinous Rectal Adenocarcinoma-Differences in Treatment Response to Preoperative Radiotherapy.

There is a need to personalize the treatment for rectal cancer patients. The aim of this study was to analyze therapy response and prognosis after preoperative radiotherapy in rectal cancer patients with mucinous adenocarcinoma compared to those with non-mucinous adenocarcinoma. The study included retrospectively collected data from 433 patients, diagnosed with rectal cancer in the South East health care region in Sweden between 2004 and 2012. Patients with non-mucinous adenocarcinoma that received short-course radiotherapy before surgery had better overall survival, cancer specific survival, and disease-free survival, as well as distant- and local-recurrence-free survival (p = 0.003, p = 0.001, p = 0.002, p = 0.002, and p = 0.033, respectively) compared to the patients that received long-course radiotherapy with concomitant capecitabine. The results were still significant after adjusting for sex, age, stage, differentiation, and chemotherapy in the neoadjuvant and/or adjuvant setting, except for local-recurrence-free survival that was trending towards significance (p = 0.070). In patients with mucinous adenocarcinoma, no difference in survival was seen when comparing patients that had short-course radiotherapy and patients that had long-course radiotherapy. However, none of 18 patients with mucinous adenocarcinoma treated with long-course radiotherapy had local tumor progression, compared to 7% of 67 patients with non-mucinous adenocarcinoma. The results indicate that mucinous adenocarcinoma and non-mucinous adenocarcinoma may respond differently to radiotherapy.

From palliative to curative treatment - stage IV mucinous adenocarcinoma, successfully treated with metronomic capecitabine in combination with Bevacizumab and surgery- a case report.

BACKGROUND: Mucinous adenocarcinoma (MAC) represents 6-19 % of all colorectal carcinoma. It is associated with poorer response to chemotherapy and chemoradiotherapy. CASE PRESENTATION: A 27-year-old Swedish woman presented with stomach pain and weight loss, and was diagnosed with locally advanced MAC in the transverse colon as well as 3 liver metastases. Neoadjuvant treatment with fluorouracil, folinic acid and oxaliplatin (FLOX) failed due to several infections, pulmonary embolism and deteriorated performance status. The patient was therefore considered palliative. Palliative treatment with metronomic capecitabine 500 mg × 2 daily and bevacizumab every other week were initiated. After 4 months of treatment the tumors had regressed and the patient was able to undergo radical surgery, thereby changing the treatment intention from palliative to curative. No adjuvant chemotherapy was given. There were no signs of recurrence 9 months later. CONCLUSIONS: The role of the combination of metronomic capecitabine and bevacizumab in patients with MAC merits further investigation.