Can pre-diagnostic serum levels of sodium and potassium predict prostate cancer survival?

Tumor volume reduction after induction chemotherapy with gemcitabine plus cisplatin in nasopharyngeal carcinoma

OBJECTIVES

To evaluate the tumor volume reduction after induction chemotherapy (IC) with gemcitabine plus cisplatin (GP) and to build prediction models for tumor volume reduction in nasopharyngeal carcinoma (NPC).

METHODS

NPC patients who received GP IC were retrospectively enrolled. The gross tumor volume of the nasopharynx and lymph nodes (GTVnx and GTVnd) were contoured before and after IC. Univariate and multivariate analyses were performed to identify associated factors. Nomogram models were constructed to predict the possibility of tumor volume reduction.

RESULTS

A total of 192 patients were enrolled. The mean relative volume reduction for GTVnx and GTVnd was 29.66% and 31.75%, respectively. The volume reduction of GTVnx and GTVnd had a weak association (r = 0.229, p < 0.001). For GTVnx volume reduction, pre-treatment neutrophil count (p = 0.043), lymphocyte count (p = 0.026), LDH level (p = 0.005), and BMI (p = 0.020) were independently associated factors. For GTVnd volume reduction, pre-treatment EBV-DNA (p = 0.029), GTVnd volume (p < 0.001), eosinophil count (p = 0.043), NLR (p = 0.039), LDH level (p = 0.026), and serum potassium level (p = 0.027) were independently associated factors. For the GTVnx nomogram model, areas under the receiver-operating characteristic curve (AUC) were 0.702 and 0.698 for the training and validation cohorts, respectively. For the GTVnd nomogram model, the AUC was 0.872 and 0.758 for the training and validation cohorts, respectively.

CONCLUSIONS

Tumor volumes reduce significantly after GP induction chemotherapy. Nomogram models for predicting the possibility of tumor volume reduction are built.

Association of Hypokalemia Incidence and Better Treatment Response in NSCLC Patients: A Meta-Analysis and Systematic Review on Anti-EGFR Targeted Therapy Clinical Trials

Background

This meta-analysis was designed to explore the relationship between the level of serum potassium and the treatment effect of epidermal growth factor receptor (EGFR) antagonist in advanced non-small cell lung cancer (aNSCLC).

Methods

We searched phase II/III prospective clinical trials on treatment with EGFR antagonists for aNSCLC patients. The objective response rate (ORR) and/or the disease control rate (DCR) and the incidence of hypokalemia of high grade (equal to or greater than grade 3) were summarized from all eligible trials. Heterogeneity, which was evaluated by Cochran’s Q-test and the I² statistics, was used to determine whether a random effects model or a fixed effects model will be used to calculate pooled proportions. Subgroup analysis was performed on different interventions, line types, phases, and drug numbers.

Results

From 666 potentially relevant articles, 36 clinical trials with a total of 9,761 participants were included in this meta-analysis. The pooled ORR was 16.25% (95%CI = 12.45–21.19) when the incidence of hypokalemia was 0%–5%, and it increased to 34.58% (95%CI = 24.09–45.07) when the incidence of hypokalemia was greater than 5%. The pooled DCR were 56.03% (95%CI = 45.03–67.03) and 64.38% (95%CI = 48.60–80.17) when the incidence rates of hypokalemia were 0%–5% and greater than 5%, respectively. The results of the subgroup analysis were consistent with the results of the whole population, except for not first-line treatment, which may have been confounded by malnutrition or poor quality of life in long-term survival.

Conclusion

The efficacy of anti-EGFR targeted therapy was positively associated with the hypokalemia incidence rate. Treatment effects on the different serum potassium strata need to be considered in future clinical trials with targeted therapy.

Fasting serum potassium and long-term mortality in healthy men

Background

Serum potassium levels have been positively associated with cardiovascular mortality, but little is known about the association with cancer mortality and death due to other causes. We examined whether serum levels of potassium were associated with long-term mortality in a healthy cohort.

Methods

Oslo Ischemia Study invited 2341 initially healthy men aged 40–59 years with no use of medication to a comprehensive health survey in 1972. Fasting serum level of potassium (mmol/L) was ascertained at baseline for 1989 men. We have complete follow-up for death throughout 2017. Cox proportional hazard models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) and adjusted for multiple confounders.

Results

After a median follow-up of 30 years (interquartile range 21.2–38.7), 1736 deaths were observed, of which 494 were cancer deaths, 688 cardiovascular deaths, and 536 deaths related to other causes. Restricted cubic spline analysis showed that potassium level was linearly and positively associated with long-term cancer mortality; HR per mmol/L 1.8, 95% CI 1.4–2.4. Compared with low levels of potassium (≤ 4.0 mmol/L), men with high levels (≥4.6 mmol/L) showed a significantly 78% higher risk of cancer death. A positive linear association was found for all-cause mortality (HR per mmol/L 1.6, 95% CI 1.4–1.8), and for cardiovascular (HR per mmol/L 1.4, 95% CI 1.1–1.7) and other cause mortality (HR per mmol/L 1.7, 95% CI 1.3–2.2).

Conclusions

These findings suggest that serum potassium level appears to predict long-term mortality in healthy middle-aged men, and it might imply future surveillance strategies for individuals with high serum potassium levels.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10738-4.

Association of Hyponatremia With Survival in Patients With Castration-resistant Prostate Cancer: A Clinical Commentary

INTRODUCTION

The aim of this study was to evaluate the prognostic value of hyponatremia in patients with castration-resistant prostate cancer (CRPC) undergoing docetaxel chemotherapy.

PATIENTS AND METHODS

We retrospectively assessed 186 patients who received docetaxel chemotherapy in addition to androgen deprivation for CRPC between 2005 and 2015. We stratified the patients according to their pre-chemotherapy serum sodium level. Hyponatremia was defined as sodium < 135 mmol/L. A Cox proportional regression model was used to estimate overall survival (OS).

RESULTS

The median sodium level was 139 mmol/L (interquartile range, 137-141 mmol/L). Hyponatremia was detected in 13 (6.9%) patients. One-half of the patients died during the studied period. The presence of hyponatremia was associated with a decreased probability of OS (hazard ratio, 2.5; 95% confidence interval, 1.0-6.3; P = .04) in univariate analysis. These findings could not be confirmed in the multivariable OS model (P = .21).

CONCLUSION

We observed an association between hyponatremia and worse survival outcomes in our patients with CRPC undergoing docetaxel chemotherapy. However, further well-designed studies with full workup of hyponatremia are needed to validate these findings and to identify the underlying causes for this association in patients with CRPC.