A longterm follow-up study of thymidylate synthase as a predictor for survival of patients with liver tumours receiving hepatic arterial infusion chemotherapy

Thymidylate synthase: a predictive biomarker in resected colorectal liver metastases receiving 5-FU treatment

AIM

To investigate the role of thymidylate synthase (TS) as a predictive biomarker in patients with resected colorectal liver metastases (CRLM).

MATERIALS & METHODS

PubMed, EMBASE and Cochrane Library were queried up to June 2017. Meta-analysis was performed using random-effects model. Risk of bias was assessed using funnel plots.

RESULTS

Six eligible studies were included, comprising a total of 542 patients. Meta-analysis demonstrated a trend to reduced overall survival in patients with resected CRLM with TS overexpression, with a hazard ratio of 1.13 (95% CI: 0.99-1.29; p = 0.08). In three studies where patients received systemic fluorouracil, the pooled hazard ratio was 2.25 (95% CI: 1.37-3.71; p = 0.001).

CONCLUSION

TS appears to be a clinically relevant predictive biomarker in patients with resected CRLM receiving systemic 5-FU.

Response prediction in metastasised colorectal cancer using intratumoural thymidylate synthase: results of a randomised multicentre trial

BACKGROUND

Molecular markers to predict response to 5-fluorouracil (FU)-based treatment of recurrent or metastasised colorectal cancer (mCRC) are not established. The aim of this trial was to determine the value of thymidylate synthase (TS), a key enzyme of DNA synthesis and target of 5-FU, to predict response to chemotherapy of mCRC.

METHODS

Tumour tissue was obtained from 168 patients with mCRC for relative thymidylate synthase (TS) mRNA quantitation. Patients were randomised to receive either 5-FU/folinic acid (FA, FUFA) alone or in combination with irinotecan 5-fluorouracil/folinic acid and irinotecan (FOLFIRI) stratified by TS (low versus high). Primary end-point was overall response to first-line treatment among TS high patients. All parties, except for the randomisation centre, were blinded for TS status.

RESULTS

Biopsies (n=168) were taken without complications. TS levels were available for 147 patients (87.5%). Analysing response to FUFA and FOLFIRI in the per protocol set (n=119) after un-blinding TS in the data base revealed a trend to better overall response to FOLFIRI (9/19, 47%) in TS high compared to FUFA (5/23, 22%, p=0.077). In patients with biopsies taken from liver lesions (n=91) overall response to FOLFIRI and FUFA in TS high was 53% (9/17) and 18% (3/17), respectively (p=0.035). In patients with low TS, no remarkable difference in overall response to FOLFIRI and FUFA was observed.

CONCLUSIONS

Taking a pre-treatment biopsy is a safe and feasible procedure in mCRC. After validation of our data in a larger group TS determination may have the potential to better help direct systemic treatment in patients with primarily non-resectable mCRC.

Thymidylate synthase expression in resectable and unresectable pancreatic cancer: role as predictive or prognostic marker?

BACKGROUND AND AIMS

Thymidylate synthase (TS) is an important enzyme for DNA synthesis and the target for 5-fluorouracil (5-FU). Its expression may determine the outcome of patients with gastrointestinal cancers. We examined the prognostic and predictive value of TS-protein expression in patients with ductal adenocarcinoma of the pancreas.

METHODS

TS expression from 131 patients with ductal adenocarcinoma of the pancreas was analyzed by immunohistochemistry in paraffin-embedded primary tumour specimens or biopsies.

RESULTS

The median disease-specific survival among all patients (n=131) was 13 months. The invasion depth, the presence of metastases, grading and Union Internationale Contre le Cancer [International Union Against Cancer] (UICC) stage were associated with survival. Among resected patients (n=98), a difference in median survival was seen in the group receiving postoperative adjuvant treatment (21.1 months) compared with the group treated by surgery alone (12.4 months) (p=0.025). Low- and high-TS immunoreactivity was present in 74 (56%) and 56 (43%) of the cancers, respectively. One sample was not evaluable. No difference in median survival was observed among low- and high-TS-expressing tumours. Among patients undergoing resection and receiving postoperative intra-arterial chemotherapy (n=23), a marked trend to a longer median survival was seen for the group with low-TS-expressing tumours compared with the corresponding high-TS group (25.0 vs 16.0 months) (p=0.3834). There was no difference in survival among all palliative treated patients with low- and high-TS-expressing tumours.

CONCLUSION

Especially patients undergoing tumour resection with low-TS values seemed to have taken advantage from an intensified postoperative chemotherapeutic protocol. However due to the heterogeneous group of patients in the present report, larger trials of more homogenous patient populations will be necessary to confirm this hypothesis.

Thymidylate synthase expression and prognosis of patients with gastrointestinal cancers receiving adjuvant chemotherapy: a review

BACKGROUND AND AIMS

Many studies have been published that report an association between thymidylate synthase (TS) and response to fluoropyrimidine-based chemotherapy and the overall outcome of patients with gastrointestinal cancer. The results have given rise to the possibility that, by determination of TS levels, the physician may decide if the patient has a potential benefit from fluoropyrimidine-based treatment, similar to measurements of oestrogen receptors in breast cancer. The purpose of this review is to summarize critically the reports on TS measurement in gastrointestinal cancer, focusing on the adjuvant fluoropyrimidine treatment situation.

METHODS

We reviewed more than 20 studies that reported the association of TS with the clinical outcome in patients with gastrointestinal cancer who had undergone complete resection of the primary tumour only or were receiving additional adjuvant chemotherapy.

RESULTS

Patients with metastasized disease who expressed high TS levels display a low probability of responding to fluoropyrimidine-based treatment and have a poorer survival rate. Patients with high TS levels who undergo complete surgical resection of the primary tumour also have a poorer prognosis than those with tumours with low TS expression. In contrast to advanced disease and to surgery alone, patients with high TS levels appear to benefit, especially, from adjuvant fluoropyrimidine-based chemotherapy after complete primary tumour resection, while patients with low TS levels do not.

CONCLUSION

Patients with gastrointestinal cancers that express high TS levels have a poor prognosis with regard to fluoropyrimidine-based palliative chemotherapy or complete primary tumour resection. In contrast, patients with high TS levels might benefit from adjuvant fluoropyrimidine-based treatment after primary tumour resection. However, additional prospective studies are mandatory to define the precise role of TS in adjuvant therapy.