Trial of an aromatic retinoid in patients with solid tumours

Retinoic acid postconsolidation therapy for high-risk neuroblastoma patients treated with autologous haematopoietic stem cell transplantation

BACKGROUND

Neuroblastoma is a rare malignant disease and mainly affects infants and very young children. The tumours mainly develop in the adrenal medullary tissue, with an abdominal mass as the most common presentation. About 50% of patients have metastatic disease at diagnosis. The high-risk group is characterised by metastasis and other features that increase the risk of an adverse outcome. High-risk patients have a five-year event-free survival of less than 50%. Retinoic acid has been shown to inhibit growth of human neuroblastoma cells and has been considered as a potential candidate for improving the outcome of patients with high-risk neuroblastoma. This review is an update of a previously published Cochrane Review.

OBJECTIVES

To evaluate the efficacy and safety of additional retinoic acid as part of a postconsolidation therapy after high-dose chemotherapy (HDCT) followed by autologous haematopoietic stem cell transplantation (HSCT), compared to placebo retinoic acid or to no additional retinoic acid in people with high-risk neuroblastoma (as defined by the International Neuroblastoma Risk Group (INRG) classification system).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (2016, Issue 11), MEDLINE in PubMed (1946 to 24 November 2016), and Embase in Ovid (1947 to 24 November 2016). Further searches included trial registries (on 22 December 2016), conference proceedings (on 23 March 2017) and reference lists of recent reviews and relevant studies. We did not apply limits by publication year or languages.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating additional retinoic acid after HDCT followed by HSCT for people with high-risk neuroblastoma compared to placebo retinoic acid or to no additional retinoic acid. Primary outcomes were overall survival and treatment-related mortality. Secondary outcomes were progression-free survival, event-free survival, early toxicity, late toxicity, and health-related quality of life.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

The update search did not identify any additional studies. We identified one RCT that included people with high-risk neuroblastoma who received HDCT followed by autologous HSCT (N = 98) after a first random allocation and who received retinoic acid (13-cis-retinoic acid; N = 50) or no further therapy (N = 48) after a second random allocation. These 98 participants had no progressive disease after HDCT followed by autologous HSCT. There was no clear evidence of difference between the treatment groups either in overall survival (hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.46 to 1.63; one trial; P = 0.66) or in event-free survival (HR 0.86, 95% CI 0.50 to 1.49; one trial; P = 0.59). We calculated the HR values using the complete follow-up period of the trial. The study also reported overall survival estimates at a fixed point in time. At the time point of five years, the survival estimate was reported to be 59% for the retinoic acid group and 41% for the no-further-therapy group (P value not reported). We did not identify results for treatment-related mortality, progression-free survival, early or late toxicity, or health-related quality of life. We could not rule out the possible presence of selection bias, performance bias, attrition bias, and other bias. We judged the evidence to be of low quality for overall survival and event-free survival, downgraded because of study limitations and imprecision.

AUTHORS' CONCLUSIONS

We identified one RCT that evaluated additional retinoic acid as part of a postconsolidation therapy after HDCT followed by autologous HSCT versus no further therapy in people with high-risk neuroblastoma. There was no clear evidence of a difference in overall survival and event-free survival between the treatment alternatives. This could be the result of low power. Information on other outcomes was not available. This trial was performed in the 1990s, since when many changes in treatment and risk classification have occurred. Based on the currently available evidence, we are therefore uncertain about the effects of retinoic acid in people with high-risk neuroblastoma. More research is needed for a definitive conclusion.

Retinoic acid post consolidation therapy for high-risk neuroblastoma patients treated with autologous hematopoietic stem cell transplantation

BACKGROUND

Neuroblastoma is a rare malignant disease and mainly affects infants and very young children. The tumors mainly develop in the adrenal medullary tissue and an abdominal mass is the most common presentation. About 50% of patients have metastatic disease at diagnosis. The high-risk group is characterized by metastasis and other characteristics that increase the risk for an adverse outcome. High-risk patients have a five-year event-free survival of less than 50%. Retinoic acid has been shown to inhibit growth of human neuroblastoma cells and has been considered as a potential candidate for improving the outcome of patients with high-risk neuroblastoma.

OBJECTIVES

To evaluate efficacy and adverse events of retinoic acid after consolidation with high-dose chemotherapy followed by bone marrow transplantation as compared to placebo or no therapy in patients with high-risk neuroblastoma (as defined by the International Neuroblastoma Risk Group (INRG) classification system). Our outcomes of interest were overall survival and treatment-related mortality as primary outcomes; and progression- and event-free survival, early and late toxicity, and health-related quality of life as secondary outcomes.

SEARCH METHODS

We searched the electronic databases CENTRAL (2014, Issue 8) on The Cochrane Library, MEDLINE (1946 to October 2014), and EMBASE (1947 to October 2014). Further searches included trial registries, conference proceedings, and reference lists of recent reviews and relevant articles. We did not apply limits on publication year or languages.

SELECTION CRITERIA

Randomized controlled trials (RCTs) evaluating retinoic acid post consolidation therapy for high-risk neuroblastoma patients treated with autologous hematopoietic stem cell transplantation (HSCT) compared to placebo or no further treatment.

DATA COLLECTION AND ANALYSIS

Two review authors performed the study selection, extracted the data on study and patient characteristics and assessed the risk of bias independently. We resolved differences by discussion or by appeal to a third review author. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. The authors of the included study did not report the results specifically for the treatment groups relevant to this Cochrane Review. Therefore, we deduced the appropriate survival data from the published survival curves and calculated a hazard ratio (HR) based on the deduced data.

MAIN RESULTS

We identified one RCT (CCG-3891) that included patients with high-risk neuroblastoma who received high-dose chemotherapy followed by autologous HSCT (N = 98) after a first random allocation and who received retinoic acid (13-cis-retinoic acid; N = 50) or no further therapy (N = 48) after a subsequent second random allocation. These patients had no progressive disease after consolidation therapy. There was no clear evidence of difference between the treatment groups in both overall survival (HR 0.87, 95% CI 0.46 to 1.63; one trial; P = 0.66, low quality of evidence) and event-free survival (HR 0.86, 95% CI 0.50 to 1.49; one trial; P = 0.59, low quality of evidence). We calculated these HR values using the complete follow-up period of the trial. The study also reported five-year overall survival rates: 59% for the retinoic acid group and 41% for the no further therapy group (P value not reported). We did not identify results for treatment-related mortality, progression-free survival, early or late toxicity, or health-related quality of life. Also, we could not rule out the possible presence of selection bias, performance bias, attrition bias, and other bias.

AUTHORS' CONCLUSIONS

We identified one RCT that evaluated retinoic acid as a consolidation therapy versus no further therapy after high-dose chemotherapy followed by bone-marrow transplantation in patients with high-risk neuroblastoma. The difference in overall survival and event-free survival between both treatment alternatives was not statistically significantly different. This could be the result of low power. Information on other outcomes was not available. This trial was performed in the 1990s, since then many changes in for example treatment and risk classification have occurred. Therefore, based on the currently available evidence, we are uncertain about the effects of retinoic acid in patients with high-risk neuroblastoma. More research is needed for a definitive conclusion.

The use of retinoids in ovarian cancer: a review of the literature

Ovarian cancer is the deadliest of all gynecologic malignancies. The search for novel treatment modalities to augment traditional chemotherapy and improve quality of life is ongoing. Retinoids, a class of compounds composed of vitamin A, its natural derivatives, and synthetic analogs, have been studied extensively in both the prevention and treatment of gynecologic malignancies. In this article, we reviewed preclinical studies and clinical trials conducted using retinoids in ovarian cancer.

Physiological and clinical aspects of vitamin A and its metabolites

Retinoids, including retinol and retinoic acid (RA), are a group of naturally occurring and synthetic compounds that exhibit vitamin A-like biological activity. They achieve their effects by binding to intracellular proteins. Important sites of action are the nuclear retinoic acid receptors (RAR). These receptors, namely, RAR alpha, RAR beta, and RAR gamma, function as transcription factors by binding to RA-responsive elements (RARE) of multiple genes. Retinoids play a role in vision, embryogenesis, immune modulation, growth and differentiation of normal, premalignant and malignant tissues, the suppression of carcinogenesis, and the inhibition of tumor growth in experimental systems and humans. Reports of the significant antitumor effect of all-trans-RA in acute promyelocytic leukemia and the synthesis of new, less toxic, and more potent retinoids has generated renewed interest in these compounds. Retinoids may have an important role to play in the chemoprevention and therapy of cancer.

Treatment of advanced malignant melanoma with interferon alpha and etretinate

The combination of recombinant human interferon alpha A 9 MU daily intramuscularly and etretinate 50 mg daily orally was given to 25 patients with progressive advanced, metastatic melanoma. The treatment was well tolerated. Partial responses were seen in three (12%) patients lasting from 2 to 8 months. A further partial response was seen in one of three patients when they were given vindesine and DTIC whilst they continued receiving interferon and etretinate.

Retinoic acid (RA): an inhibitor of 5 alpha-reductase in human prostatic cancer cells

The effect of retinoic acid (RA) on testosterone metabolism was examined in a prostatic cancer cell line of human origin, PC-3. In cells growing as monolayers as well as in cell homogenates RA causes a dose-dependent inhibition of the 5 alpha-reductase activity, thus preventing the conversion of testosterone into its hormonally active metabolite, dihydrotestosterone. Fifty per cent inhibition of the enzyme activity occurred at an RA concentration of 2 x 10(-5)M. The pattern of inhibition was that of a non-competitive inhibitor. However, when incubations were performed in the presence of varying amounts of NADPH, it turned out that RA exerts its effect by competitive inhibition of the cofactor action. Although the severe toxicity of RA precludes its systemic use as a 5 alpha-reductase inhibitory drug in humans, the possible anti-androgenic effect of other, less toxic, retinoids should be investigated.

Malignant disease: nutritional implications of disease and treatment

Protein-energy malnutrition (PEM) is common in cancer patients and may develop into the syndrome known as 'cancer cachexia'. This is characterised by complex disturbances in carbohydrate, lipid, protein, and electrolyte metabolism. The aetiology is equally complex, with host and therapeutic factors contributing to the reduced food intake and effects on host tissues. Anorexia is of prime importance, differing in its cause from one patient to another and often presenting a barrier to successful nutritional support. Further research is necessary to elucidate the interaction of central and peripheral factors that may be involved in the aetiology of anorexia. Because of the interplay of biochemical, physiological, and psychological consequences of cancer, the nutritional support of the patient presents a considerable challenge to the caring professions.

The retinoids. A review of their clinical pharmacology and therapeutic use

With the introduction of the synthetic retinoids, oral therapy with an acceptable risk/benefit ratio became possible for a variety of skin diseases including severe acne, psoriasis and numerous genodermatoses. This article reviews the clinical pharmacology, mechanisms of action and therapeutic use of the retinoids, particularly isotretinoin (13-cis-retinoic acid) and etretinate. The free aromatic acid of etretinate, etretin, and the new polyaromatic retinoid compounds (arotinoids) are also discussed. Isotretinoin is used clinically for oral therapy of severe acne, but is also recommended for severe Gram-negative folliculitis and rosacea not responding to traditional therapy. The results of several studies have established that acne therapy should be started with 1.0 mg/kg/day for 2 to 3 months after which the daily dosage should be lowered to 0.2 to 0.5 mg/kg/day for another 2 to 3 months. This therapeutic regimen of isotretinoin has proven to be the most successful in preventing relapses. Etretinate is particularly useful for oral therapy of widespread plaque-like, pustular and erythrodermic psoriasis, and of generalised lichen planus, Darier's disease and severe congenital ichthyoses. Whereas pustular forms of psoriasis require a high daily dosage of 1.0 mg/kg/day, erythrodermic psoriasis should be treated with a lower dosage of 0.25 to 0.35 mg/kg/day. In chronic plaque-like psoriasis, a mean daily dosage of 0.5 mg/kg/day over several weeks to months, usually combined with photo(chemo)therapy, tar or dithranol, is recommended. Other indications for oral etretinate therapy are adequately treated with a moderate dosage of 0.4 to 0.75 mg/kg/day. Etretin differs from etretinate in having a much shorter elimination half-life of 2 to 3 days, in contrast to 80 to 100 days after long term administration of etretinate. Moreover, it has not been shown to increase serum cholesterol levels. However, its clinical efficacy is not yet clearly established. Among the arotinoids, arotinoid ethylester (Ro 13-6298) has revealed the best anti-psoriatic and anti-inflammatory effects at extremely low dose levels. Furthermore, no significant elevations of serum lipids have been observed. Taking its prolonged elimination half-life and its efficacy/side effect ratio into account, the drug is comparable to etretinate. The free arotinoid carboxylic acid (Ro 13-7410) is currently undergoing clinical investigation. Another arotinoid, the parent compound Ro 15-0778, has not demonstrated any convincing clinical efficacy in acne or psoriasis, but topical anti-inflammatory effects were evident in some models.(ABSTRACT TRUNCATED AT 400 WORDS)