Response of glutathione S-transferase Pi (GSTP1) to neoadjuvant therapy in rectal adenocarcinoma.

AIM: The response of rectal adenocarcinoma to neoadjuvant therapy is variable. Accurate prediction of response would enable selective administration of therapy. The enzyme glutathione S-transferase Pi (GSTP1) has been shown to influence response to therapy in some solid tumours. Few data are available for rectal cancer. METHOD: The GSTP1 levels in rectal adenocarcinoma and adjacent normal mucosa were quantified before and after exposure to neoadjuvant therapy. Venous blood samples and biopsies of normal rectal mucosa and tumour were prospectively obtained from patients with primary rectal cancer. Patients were stratified by exposure to neoadjuvant therapy or surgery alone. GSTP1 was quantitatively measured using an enzyme-linked immunosorbent assay. RESULTS: Ninety-two patients (54 men; median age 68 years) were recruited. The median GSTP1 level was significantly higher in rectal adenocarcinoma than in matched normal mucosa [6.59 µg/mg vs 4.57 µg/mg; P < 0.001]. The median tumour GSTP1 level was significantly lower in the therapy group compared with unmatched samples from the no-therapy group [4.47 µg/mg vs 7.76 µg/mg; P < 0.001]. CONCLUSION: The GSTP1 level is increased in rectal adenocarcinoma compared with adjacent normal mucosa. It decreases following neoadjuvant therapy. Future studies correlating pre-therapy GSTP1 levels with pathological response would be of interest.

Acute kidney injury.

Acute kidney injury (AKI) represents a medical emergency associated with poor clinical outcomes. The international guideline group Kidney Disease: Improving Global Outcomes (KDIGO) has defined AKI according to rises in serum creatinine and/or reductions in urine output. Any patient who meets the criteria for AKI should be reviewed to ascertain the cause of AKI and the severity of the injury should be staged. Patients with more severe AKI are at greater risk of progression to chronic kidney disease (CKD). The 2009 National Confidential Enquiry into Patient Outcomes and Death (NCEPOD) reported that only 50% of patients who died with a diagnosis with AKI received good care. The mortality from AKI has remained unchanged for the last four decades and there are currently no specific therapies for the majority of cases of AKI. Patients with rarer forms of AKI need urgent renal referral for specific therapy. At present, serum creatinine and urine output remain the best biomarkers for detecting AKI. However, significant kidney damage has usually occurred by the time changes in these biomarkers are manifest and newer biomarkers are under investigation. Management of AKI is based upon general supportive measures, which includes treatment of the underlying cause and the initiation of renal replacement therapy (RRT) in patients with complications refractory to medical management. The optimal choice of intravenous fluid therapy remains controversial. There is currently renewed interest in more specific therapies for AKI secondary to hypoperfusion and/or sepsis, which have been previously unsuccessful. A number of therapeutic strategies are presently being explored in clinical trials.