Syndrome of inappropriate antidiuretic hormone secretion (SIADH) in patients with limited stage small cell lung cancer

Syndrome of inappropriate antidiuretic hormone secretion

Hyponatremia is the most frequent electrolytic disorder in hospitalized patients, and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), the most frequent cause of hiponatremia with clinically normal extracellular volume. It consists of a disorder of the regulation of body water that obeys to different causes, mainly cancer, pulmonary illnesses, disorders of the central nervous system and diverse drugs. As in any hiponatremia it a physiological knowledge of the regulation of body water and sodium is essential as well as the application of precise diagnostic criteria in order to manage the problem with an effective treatment. The available data until the moment show that the clinical diagnosis of SIADH made by professionals is mainly not supported on the established criteria drawn by experts and this lack of accuracy probably hits in the therapeutic result. The basis of the treatment of the SIADH is to correct its cause, water restriction, solutes (sodium chloride) and the use of vaptans in case of failure of the previous measures.

Syndrome of Inappropriate Antidiuretic Hormone Secretion as the Initial Presentation in a Patient with Stage I Small-cell Lung Cancer

A 67-year-old man with a history of esophageal cancer resection was referred to our hospital because of nausea and appetite loss. Laboratory findings showed severe hyponatremia and were compatible with syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Chest computed tomography (CT) revealed a nodule measuring 13 mm in the lower lobe of the right lung. Right thoracotomy was performed, and the histopathological diagnosis was small-cell lung cancer (T1bN0M0; Stage 1b). Although SIADH is frequently associated with small-cell lung cancer, it is extremely rare as the initial clinical feature in stage I small-cell lung cancer.

Paraneoplastic Syndromes in Lung Cancers: Manifestations of Ectopic Endocrinological Syndromes and Neurologic Syndromes

Paraneoplastic syndromes are clinical entities associated with cancers and often overlap with metabolic and endocrine syndromes. The cell types of lung cancer involved are frequently small cell, squamous cell, adenocarcinoma, large cell, and carcinoid tumor. A number of neurologic paraneoplastic syndromes have been described for which the tumor product remains unknown. These include peripheral neuropathies, a myasthenia-like syndrome, and subacute cerebellar degeneration. Although all of these syndromes may improve with successful treatment of the primary tumor, complete resolution is rare.

Small cell carcinoma of the cervix complicated by syndrome of inappropriate antidiuretic hormone secretion: a case report

Small cell carcinoma of the cervix is a rare malignant tumor in the clinical setting. Clinical manifestations of this tumor are mostly similar to those of normal types of cervical cancer. Small cell carcinoma of the cervix only shows symptoms of neuroendocrine tumors, such as syndrome of inappropriate antidiuretic hormone secretion (SIADH). Most of the hyponatremia caused by SIADH can be managed after removal of the cause. Hyponatremia is a predictor of poor prognosis and can be used as an indicator of partial recurrence. We report a case of small cell carcinoma of the cervix complicated by SIADH. Our patient presented with irregular vaginal bleeding after menopause. After one cycle of chemotherapy, there was trembling of the limbs, and a laboratory examination showed low Na⁺ and low Cl⁻ levels. After limited water intake, intravenous hypertonic saline, and intermittent diuretic treatment, the patient’s blood Na⁺ levels returned to normal. After a radical operation, the above-mentioned symptoms disappeared.

Paraneoplastic syndromes in small cell lung cancer

Paraneoplastic syndromes can commonly occur due to lung cancer, especially small cell lung cancer. Frequently paraneoplastic syndromes can precede the diagnosis of the neoplasm or present with limited stage disease. However, these syndromes can also occur at the time of recurrence or metastasis of disease. This review focuses on the epidemiology, pathogenesis, clinical features, and current management of the most common paraneoplastic syndromes encountered in patients with small cell lung cancer. Manifestations of paraneoplastic syndromes in small cell lung cancer include endocrine syndromes with secretion of excess hormones, and neurologic syndromes due to the production of antibodies causing an autoimmune condition. Recent advances have allowed for greater understanding of these syndromes and for the development of improved diagnostic as well as therapeutic tools. Awareness of paraneoplastic syndromes in small cell lung cancer can lead to an earlier diagnosis and recognition of both the condition and in some cases the disease potentially improving the overall survival and prognosis for patients. Further research examining effective methods to improve recovery from neurologic deficits in patients with a paraneoplastic neurologic illness is warranted.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH): Optimal Management

Hyponatremia, defined as serum sodium concentration <135 mEq/l, is the most common electrolyte balance disorder in clinical practice. Many causes are listed, but syndrome of inappropriate antidiuretic hormone secretion (SIADH) is certainly the most relevant, mainly in oncological and hospitalized patients. In this review, the pathophysiological and clinical aspects are described in detail. Patients' extensive medical history and structured physical and biochemical tests are considered the milestones marking the way of the SIADH management as to provide early detection and proper correction. We focused our attention on the poor prognostic role and negative effect on patient's quality of life of SIADH-induced hyponatremia in both malignant and non-malignant settings, stressing how optimal management of this electrolyte imbalance can result in improved outcomes and lower health costs.

Evaluation of Circulating Tumor Cells in Predicting Therapeutic Response in Small Cell Lung Cancer Patients

BACKGROUND AND AIMS

Circulating tumor cells (CTCs) have prognostic significance in patients with metastatic cancer, but their utility in predicting the response to tumor therapy is unknown. This study examined the correlation of CTCs with the therapeutic response in small cell lung cancer (SCLC).

METHODS

Clinical and pathological data from 96 SCLC patients were evaluated in this study. CellSearch kits were used to detect CTCs in peripheral blood samples. Statistical analysis was performed using Fisher exact test and Mann-Whitney U test.

RESULTS

At baseline, 47 (50.0%) SCLC patients had detectable CTC counts. Serum neuron-specific enolase (NSE) was found to be associated with CTC thresholds. However, no significant differences were observed for an association of any threshold CTC count with the treatment response, with gender, age (≤60 or >60 years), smoking status, syndrome of inappropriate antidiuretic hormone (SIADH), or Ki67 expression.

CONCLUSION

Detection of CTCs in SCLC patients was associated with serum NSE but not with response to cancer therapy.

Syndrome of Inappropriate Antidiuretic Hormone Secretion: A Poor Prognosis in Small-cell Lung Cancer

BACKGROUND AND AIMS

Small cell lung cancer (SCLC) is frequently associated with syndrome of inappropriate antidiuretic hormone (SIADH) secretion. In this study we investigated the prognostic value of SIADH in Chinese patients with SCLC.

METHODS

We prospectively studied a total of 385 patients with SCLC diagnosed in our institution. The relationship between the SIADH and treatment outcomes including progression-free survival (PFS) and overall survival (OS) were analyzed. Univariate analysis and Cox multivariate analyses were used for statistical analyses. PFS and OS curves were drawn using Kaplan-Meier method.

RESULTS

The median PFS and OS in patients with SIADH was 6.7 months (95% confidence interval [CI]: 4.3-9.1) and 11.6 months (95% CI: 7.4-15.7), respectively. The corresponding PFS and OS in SCLC without SIADH was 9.2 months (95% CI: 8.6-9.8) and 19.2 months (95% CI: 16.5-21.9), respectively; the difference between groups was statistically significant (p = 0.007 and p = 0.000, respectively). The association of SIADH with poor PFS (p = 0.000) and OS (p = 0.002) retained its statistical significance after adjusting for potential confounding variables. In addition, PFS (p = 0.000) and OS (p = 0.000) of SIAHD patients with plasma sodium <125 mmol/L or without plasma sodium recovery to normal level are both shorter than in patients without SIADH. OS in SIAHD patients with plasma sodium recovery time to normal level is also shorter than patients without SIADH (p = 0.03).

CONCLUSIONS

SIADH is a common occurrence in patients with SCLC and is associated with poor prognosis for SCLC in Chinese patients.

Progress in the management of limited-stage small cell lung cancer

Approximately 15% of lung cancer cases are of the small cell subtype, but this variant is highly aggressive and is often diagnosed at advanced stages. Outcomes after current treatment regimens have been poor, with 5-year survival rates as low as 25% for patients with limited-stage disease. Advances in therapy for small cell lung cancer have included the development of more effective chemotherapeutic agents and radiation techniques. For example, hyperfractionated radiotherapy given early in the course of the disease can reduce local recurrence and extend survival. Other technologic advances in radiation planning and delivery such as intensity-modulated radiotherapy, image-guided adaptive radiotherapy, and 4-dimensional computed tomography/positron emission tomography have facilitated the design of treatment volumes that closely conform to the shape of the tumor, which allows higher radiation doses to be given while minimizing radiation-induced toxicity to adjacent structures. Future improvements in outcomes will require clarifying the molecular basis for this disease.

Small cell neuroendocrine carcinoma of the uterine cervix presenting with syndrome of inappropriate antidiuretic hormone secretion

Small cell carcinoma of the uterine cervix is rare. It is estimated that 10% of patients with small-cell lung cancer have syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and hyponatremia has been reported to be significantly associated with a poor prognosis. A proportion of small cell carcinoma of the uterine cervix exhibit neuroendocrine characteristics as revealed by immunohistochemistry, However, cases presenting typical symptoms due to SIADH are extremely rare. This report of the SIADH of the uterine cervix is a rare case in the small cell carcinoma of the cervix presenting with tumor-associated paraneoplastic syndrome.

The Incidence of Hyponatraemia and Its Effect on the ECOG Performance Status among Lung Cancer Patients

CONTEXT

Hyponatraemia is one of the common electrolytic disorders which are associated with lung cancer. Hyponatraemia may influence the ECOG performance status at presentation. Also, to the best of our knowledge, we found only limited Indian studies where the ECOG score was correlated with the serum sodium status in lung cancer patients on presentation.

AIM

To assess the incidence of hyponatraemia among the patients of carcinoma of the lung before putting them into the specific treatment category for cancer and to check the effects on their ECOG performance status.

SETTINGS AND DESIGN

A cross-sectional, observational study was conducted on 116 consecutive patients of lung cancer during the period from November 2011 to October 2012.

MATERIAL AND METHODS

The patients with a histologically proven diagnosis of lung cancer were grouped initially according to their ECOG performance statuses. The serum sodium value of each patient was measured and the hyponatraemic patients were given treatment according to the protocol. The correlation of the ECOG performance status with the serum sodium of the lung cancer patients was measured. To check for any laboratory error in serum sodium, we selected (n = 58) age, sex and socioeconomic matched control patients.

RESULTS

At presentation 44.8% of the lung cancer patients showed hyponatraemia [52/116]. The ECOG score was significantly poor in the advanced clinical stages (ECOG ≤2 Vs ECOG ≥ 3 in NSCLC cases, χ(2) =11.25, P=.0008). The ECOG performance status score at admission showed a negative correlation with the serum sodium status which was measured on admission among all the patients (Pearson correlation coefficient = - 0.186). The clinical stage of the lung cancer also showed a positive correlation with the ECOG score at admission in our study (Pearson correlation coefficient = 0.295).

CONCLUSION

Hyponatraemia is not an uncommon condition and it should be suspected and screened in each patient, as it may influence the ECOG performance status score, which serves as an important factor in the prognosis of lung cancer.

Is hyponatremia mistreated? Challenging the current paradigm

BACKGROUND

Hyponatremia is a common but often mistreated clinical situation in the ICU. This often requires the physician to identify the underlying problem, adrenal insufficiency. However, by the textbook, the current treatment always involves sodium chloride supplementation to hyponatremic patients, either intravenous or oral intake. We hypothesize that the mechanism behind most hyponatremia is most likely to be the sodium and water redistribution from the serum to the cells or the interstitial spaces due to the insufficient cortical steroid, not the sodium deficiency. As we have no reason to believe the patients have lost that much sodium which caused hyponatremia. Therefore, giving this type of hyponatremic patients (adrenal insufficient) sodium chloride is always ineffective and sometimes catastrophic.

METHODS

We discuss the possible mechanism for hyponatremia in critically ill/post surgery patients who are mostly likely to be adrenal insufficient rather than absolute sodium deficiency. In combination with many other common but unexplainable symptoms such as nausea, vomiting, obstinate diarrhea, hypotension and coma in the ICU, it is highly likely that hyponatremia is a condition which reflects the patients' adrenal function. The evidence supporting our hypothesis is that, (1) the serum sodium level does not always respond well to sodium supplementation therapy; (2) those aforementioned symptoms alleviated simultaneously with the serum sodium level returned to normal after the hydrocortisone or prednisone was administered without any oral/intravenous sodium supplementation; (3) patient with an elevated serum/urine cortisol level suffers from aforementioned unexplainable symptoms does not warrant him being adrenal sufficient. If the patient also has hyponatremia, the diagnosis can be considered as "relative adrenal insufficiency" and the patient would respond well to hydrocortisone or prednisone therapy.

CONCLUSIONS

We hypothesize that hyponatremia without significant loss of sodium can be used as an indicator to monitor the patients' adrenal function regardless of the serum/urine cortisol level. Furthermore, we propose a novel approach toward hyponatremia treatment in critically ill patients would be hydrocortisone or prednisone therapy depending on the circumstances.

Hyponatremia as prognostic factor in small cell lung cancer--a retrospective single institution analysis

PURPOSE

The aim of this retrospective study is to present data on clinical significance of hyponatremia in an unselected contemporary patient population with small cell lung cancer (SCLC) with limited disease (LD) and extensive disease (ED).

PATIENTS AND METHODS

Our electronic database was searched for patients with newly diagnosed SCLC from June 2004 to December 2008. 395 cases were identified. We collected data on patient characteristics including clinical performance status, serum sodium values, serum LDH values, metastatic sites, chemotherapy regimens and response, radiotherapy and survival.

RESULTS

Hyponatremia (sodium <135 mmol/l) was present in 18.9% of all cases. Severe hyponatremia (sodium <129 mmol/l) was detected in 8.8%. Hyponatremia was present in 58 out of 241 (24%) patients with ED SCLC and 17 of 154 (11%) patients with LD SCLC. Hyponatremia was associated with significantly shorter median survival (SCLC all patients: 9.0 vs. 13.0 months, p < 0.001, LD SCLC: 9.0 vs. 17.0, p = 0.050, ED SCLC 9.0 vs. 10.0, p = 0.135). After adjustment for age, gender, LDH and performance status hyponatremia was an independent predictor of mortality in patients with ED and LD SCLC.

CONCLUSION

According to the extensive statistical analyses in our comprehensive unselected patient population, hyponatremia seems to constitute an independent prognostic factor in patients with SCLC.

Small cell gallbladder carcinoma complicated by paraneoplastic hyponatremia: a case report and literature review

INTRODUCTION

Gallbladder carcinoma has been associated with various paraneoplastic syndromes. These may be the presenting manifestations that lead the clinician to a diagnosis.

CASE REPORT

We report a case of small cell gallbladder carcinoma complicated by paraneoplastic hyponatremia. The hyponatremia was further exacerbated by platinum-based chemotherapy.

DISCUSSION

There have previously been no reports of paraneoplastic hyponatremia in gallbladder carcinoma. We discuss the management of this problem and also provide a short literature review on the other paraneoplastic syndromes associated with gallbladder carcinoma.

CONCLUSION

Symptoms and signs of gallbladder cancer may be insidious. Thorough workup is needed if the patient presents with symptoms and signs of a paraneoplastic syndrome.

The occurrence of hyponatremia in SCLC and the influence on prognosis: a retrospective study of 453 patients treated in a single institution in a 10-year period

Hyponatremia is often seen in SCLC, and is thought to be caused by the paraneoplastic syndrome SIADH. Variable results of the prognostic significance of low P-sodium (P-Na) have been reported. This study was performed to investigate the prognostic value of hyponatremia in SCLC. Data was obtained from files from 453 patients diagnosed with SCLC and treated at Odense University Hospital from 1995 to 2005 in which data on P-sodium was available. The standard chemotherapy was six cycles of carboplatin-etoposide. P-Na was <125 mEq/L in 47 patients (11%) and 126-135 mEq/L in 151 (33%), and 255 patients (56%) showed normal values. The median survival was 11.2 months in patients with normal P-Na, and 7.1 months in patients with subnormal values (p=0.0001). In a Cox multivariate analysis of the 402 patients treated with carboplatin-etoposide, hyponatremia was associated with poorer prognosis. Other independent prognostic factors included LDH, gender, age, performance status, stage, and low value of albumin. Treatment prior to year 2000 was of border line significance, while in-significant factors included hemoglobin level, WBC and alkaline phosphatase. In 61 patients with P-Na <130 mEq/L receiving two or more cycles of chemotherapy, only 15 of the 61 patients (25%) normalized the value of P-Na to 136 mEq/L or above at the time of the second cycle of chemotherapy. The patients who did not fully regain normal values of P-Na, had poorer survival compared with the patients who did in a univariate analysis (p=0.027), and in a Cox multivariate analysis. In conclusion, hyponatremia was a significant prognostic factor associated with poor prognosis and so was failure to normalize P-Na within the first two cycles of chemotherapy.

Small cell neuroendocrine carcinoma of the ethmoid sinuses presenting with generalized seizure and syndrome of inappropriate antidiuretic hormone secretion: a case report and review of literature

Small cell neuroendocrine carcinoma of the paranasal sinuses is extremely rare. We present a case of small cell neuroendocrine carcinoma of the ethmoid sinuses associated with syndrome of inappropriate antidiuretic hormone secretion that resolved after chemotherapy, followed by a review of the literature.

[Small cell lung cancer]

With about 20% of all lung cancers small cell lung cancer (SCLC) represents a major subset of this entity. Although therapeutic improvements did not receive as much attention as in non small cell lung cancer (NSCLC), many small steps of clinical progress have been achieved within the last 20 years. An optimal treatment should be based on an interdisciplinary treatment plan. The standard treatment in localized stages represents combined radiation and chemotherapy. Cisplatin and etoposide are in this concern considered as a gold standard. 3D-planned conformal radiotherapy should start as early as possible and should be applied concomitantly to chemotherapy and in certain cases even in a hyperfractionated treatment protocol. In very early stages surgical resection could be an option in selected cases. In advanced stages a platinum-based doublet offers high response rates. As already established in limited disease prophylactic cranial irradiation is now also indicated in extensive disease in case of any tumor remission. In the second line treatment and in patients with reduced performance status topotecan is recommended. Similar as in NSCLC pemetrexed might become an alternative treatment option in the second line setting. In the field of new targeted therapies bevacizumab achieved the most promising results. The present review highlights historical milestones and up-to-date trends in radiotherapy, chemotherapy and surgery. Furthermore, the role of experimental strategies and the management of certain special clinical situations are discussed.

Hyponatremia: current treatment strategies and the role of vasopressin antagonists

OBJECTIVE

Hyponatremia is a complex electrolyte disorder that results mainly from dysregulation of arginine vasopressin (AVP) by osmotic and nonosmotic mechanisms. Several populations, including the elderly, are at risk for the development of hyponatremia, and awareness of such risk factors can lead to an overall improvement in patient care. AVP receptor antagonists are promising new therapeutic options whose safety and efficacy have been clinically established for some forms of hyponatremia.

DATA SOURCES

A search of MEDLINE (1967-March 2007) was conducted, using the search terms aquaporins, AVP, AVP receptor antagonists, conivaptan, hyponatremia, lixivaptan, and tolvaptan. Additionally, data were obtained from manufacturers' prescribing information.

STUDY SELECTION AND DATA EXTRACTION

All articles identified from the reference search and data sources were evaluated. Material was included in this review if it was relevant to the pathophysiology and management of euvolemic and hypervolemic hyponatremia in hospitalized patients.

DATA SYNTHESIS

A large percentage of hospitalized patients are found to have symptomatic or asymptomatic hyponatremia. One study reported that 24.5% of intensive care patients admitted over a 3 month period experienced hyponatremia at some time during their hospitalization. Conventional management techniques include water restriction, demeclocycline, lithium, and urea, which have demonstrated variable efficacy and toxicity. AVP receptor antagonists, whose safety and efficacy have been established in clinical trials, are providing new therapeutic options.

CONCLUSIONS

AVP receptor antagonists appear to be safe and effective for the treatment of patients with hyponatremia. With conivaptan recently approved by the Food and Drug Administration for use in treating euvolemic and hypervolemic hyponatremia in hospitalized patients and lixivaptan and tolvaptan in the late stages of development, prudent use of these agents requires a thorough understanding of the clinical manifestations of hyponatremia to optimize therapeutic outcomes.

Serum level of arginine-vasopressin influences the prognosis of extensive-disease small-cell lung cancer

PURPOSE

The purpose of this study is to elucidate the influence of serum arginine-vasopressin (AVP) level on prognosis of extensive-disease small-cell lung cancer (ED-SCLC).

METHODS

We retrospectively investigated the clinical records of 163 patients with ED-SCLC, who were admitted to Okayama University Hospital or National Shikoku Cancer Center Hospital. The influence of 14 pretreatment variables on survival was analyzed.

RESULTS

In a multivariate analysis of 163 patients, elevation of serum LDH level (P = 0.028) and poor performance status (PS > or = 2, P = 0.002) were independent poor prognostic factors. In 34 patients whose serum AVP levels were available, high serum AVP level was related to the poor prognosis (P < 0.001). The serum-sodium level did not affect the survival. Median serum level of osmotic pressure in 34 patients was normal (284.9 mOsm/kg), although, serum osmotic pressure was low in four of six patients with high serum AVP level. In all patients with high serum AVP level, serum LDH level was elevated.

CONCLUSIONS

The data from the current study suggested that serum LDH level and PS were the poor prognostic factors for ED-SCLC. But we additionally identified the prognostic significance of serum AVP level, which may be a more useful factor than serum-sodium level.