Therapeutic efficacy, prognostic variables and clinical outcome of 177Lu-PSMA-617 PRLT in progressive mCRPC following multiple lines of treatment: prognostic implications of high FDG uptake on dual tracer PET-CT vis-à-vis Gleason score in such cohort

OBJECTIVE

To evaluate the therapeutic response, progression free survival (PFS), overall survival (OS) and clinical toxicity of ¹⁷⁷Lu-PSMA-617 PSMA targeted radioligand therapy (PRLT) in the setting of heavily pre-treated metastatic castrate-resistant prostate cancer (mCPRC) patients and also examine the association of prognostic variables with therapeutic outcome in such patient cohort.

METHODS

We examined the medical records of mCRPC patients who had undergone ¹⁷⁷Lu-PSMA-617 PRLT from March 2017 to February 2019 in our institute. Patients receiving equal to or more than two cycles were included and analyzed in this retroprospective study.The ⁶⁸Ga-PSMA-11 PET-CT and 18-fludeoxyglucose positron emission tomography (¹⁸FDG PET)-CT scan findings, serum prostate-specific antigen (PSA) change, health-related quality of life (HRQoL) scales (Eastern Cooperative Oncology Group/Karnofsky score) and Gleason score were assessed for their implications on the outcome of therapy. The treatment response was evaluated under three categories: (a) symptomatic (b) biochemical and (c) imaging response.The PFS and OS following first PRLT were determined and the association of various variables with PSA doubling time (DT) and FDG uptake in the lesions were analyzed. Toxicity assessment was undertaken objectively by National Cancer Institute-Common Terminology Criteria for Adverse Events scale v. 5.0 for haematological and nephrotoxicity, and salivary gland toxicity assessed by xerostomia inventory score.

RESULTS

A total of 40 mCRPC patients (age range: 46-84 years; median 63 years), who had undergone ¹⁷⁷Lu-PSMA-617 PRLT, of at least two cycles was identified and selected for the analysis. FDG uptake was noted in 87.5% of patients (n = 35). Out of 40 cases, 21 were responders (CR, PR and SD) and 19 were non-responders (PD) on symptomatic and biochemical scales while on molecular imaging response, 16 (43%) were responders and remaining 21 (57%) were non-responders. Lesion-wise, ⁶⁸Ga-PSMA-11 avid metastatic nodal disease responded well with ¹⁷⁷Lu PSMA-617 PRLT, as compared to hepatic and skeletal lesions. The median OS and PFS was 12 and 7 months respectively following first PRLT. Patients with negative serum PSA-DT demonstrated superior 1 year PFS as compared to those with positive serum PSA-DT (52.5 vs 47.5%) (p = 0.029). Patients receiving greater than two cycles PRLT demonstrated a higher negative PSA-DT as compared to those receiving two cycles (p-value = 0.03). Grade 1 xerostomia was observed in two patients (5%) (mean xerostomia score of 23), haematotoxicity in seven patients [Grade I (n = 2, 5%) and Grade II (n = 5, 14%)].

CONCLUSION

¹⁷⁷Lu-PSMA-617 PRLT was well-tolerated and able to produce disease control with good symptomatic and biochemical responses in the context of heavily pre-treated mCRPC with progressive disease, with low toxicity profile. Evident association of high FDG uptake was observed with aggressive disease biology coupled with increasing Gleason score and poorer 12 months PFS. Negative PSA-DT following therapy demonstrated longer PFS. The results demonstrate important future role of ¹⁷⁷Lu-PSMA-617 PRLT in the treatment of mCRPC.

ADVANCES IN KNOWLEDGE

The present work explored in a large teriary cancer care setting, the efficacy of ¹⁷⁷Lu-PSMA-617 PRLT, in an aggressive and unselected subset of mCRPC. The response and outcome was correlated with a number of prognostic variables, including molecular imaging findings (FDG uptake in the metastatic lesions), PSA DT and Gleason score.

Comparison of Salivary Calcium Level in Dentulous and Edentulous Patients

OBJECTIVES

Calcium is an inorganic component of the saliva, which is especially important in oral and dental health. This study sought to compare unstimulated salivary calcium level of dentulous and edentulous patients.

MATERIALS AND METHODS

This case-control study was conducted on 72 participants, including 36 dentulous and 36 edentulous patients. The unstimulated salivary flow rate of patients and the mean salivary calcium concentration were measured and compared. The data were analyzed using the nonparametric Mann-Whitney U-test.

RESULTS

The mean age of participants was 56.3 years. The mean number of teeth was 18.9 in the dentulous group. No significant difference was noted in salivary calcium level of dentulous and edentulous patients. The mean salivary calcium concentration was 0.61 ± 0.3875 mmol/L in dentulous and 0.8025 ± 0.5975 mmol/L in edentulous patients. Salivary calcium level had a significant inverse correlation with salivary flow rate (r = -0.370, p = 0.027), and by every 1-unit increase in salivary flow rate, salivary level of calcium significantly decreased by 3.85 units.

CONCLUSION

Edentate had averagely higher salivary calcium level compared to dentulous. The salivary concentration of calcium ion is not correlated to the presence or absence of teeth. Salivary flow rate reduces the calcium concentration.

Comparative study of oral and salivary parameters in patients with and without loss of bone mass

Osteoporosis is an insidious and increasingly prevalent disease that can cause fractures and affect patients' quality of life. The current study comparatively evaluates patients with and without loss of bone mass in terms of salivary calcium, viscosity, and pH. A controlled cross-sectional study was conducted in two groups of 32 postmenopausal women subjected to a bone densitometry scan and later referred for dental management at the Federal University of Minas Gerais, Brazil. The patients were assigned to two groups: Group 1 - patients with low bone mineral density (BMD) and Group 2 - patients without bone mineral changes. The following salivary parameters were evaluated: calcium concentration, flow rate, viscosity, pH, and average total protein. An oral examination was performed for assessment of DMFT variables and tongue coating. Data were analyzed using descriptive and inferential statistics, adopting a p-value < 0.05. The patients' mean age was 60 years (± 7.35). Salivary flow, pH, and viscosity were similar among the groups. Average total protein was 14.8 mg/mL and 19.0 mg/mL in Groups 1 and 2, respectively. Tongue coating and salivary calcium levels were significantly higher in Group 1 (p < 0.001). Salivary calcium is an important screening tool and may eventually be used for the diagnosis of bone mineral changes.

Stimulated and Unstimulated Saliva Levels of Calcium and Magnesium in Giardiasis

Giardia lamblia causes malabsorption. The aim of this study was to evaluate serum and saliva calcium and magnesium levels in patients with giardiasis. Thirty patients with giardiasis as a case and 30 person without giardiasis as a control group were enrolled. The stimulated and unstimulated whole saliva and serum calcium and magnesium levels were assayed by Arsenazo reaction and xylidyl blue complex methods, respectively. Mean calcium and magnesium level was low in serum and stimulated saliva of case group than that of controls. However, they were higher in the unstimulated saliva of the case group. It is suggested that patients suffering from giardiasis have low calcium and magnesium levels, and they lose the most of calcium and magnesium by saliva during unstimulated condition.

Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus

Background

Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation.

Objective

This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus.

Method

Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA.

Results

The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form.

Limitations of the study

This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results.

Conclusions

The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further studies are needed for introducing aldehyde dehydrogenase as a prognostic indicator in certain lesions.

Evaluation of Xerostomia and salivary flow rate in Hashimoto's Thyroiditis

BACKGROUND

One of the most common causes of hypothyroidism is Hashimoto's Thyroiditis (HT). Early detection of dry mouth is critical in preserving and promoting systemic and oral health. In this study we have assessed, for the first time, salivary function and xerostomia in HT patients who have not been involved with Sjögren's syndrome.

MATERIAL AND METHODS

HT was diagnosed in 40 patients based on clinical findings and positive anti-thyroid peroxidase antibodies (anti-TPO). Controls, matched by sex, age and body mass index (BMI), and with no history of thyroid disease, were selected. A questionnaire was used for diagnosis of xerostomia. Saliva samples were taken between 8 a.m. and 9 a.m., and at least 2 hours after the last intake of food or drink. The flow rate was calculated in milliliters per minute.

RESULTS

Xerostomia was significantly higher in patients with HT. Unstimulated salivary flow rate was significantly lower in the HT group. Stimulated salivary flow rate was lower in HT group, but the difference was not significant.

CONCLUSIONS

The patients with HT experienced xerostomia, and their salivary flow rate was diminished. Spitting the saliva then assessing salivary flow rate based on milliliter per minute is non-invasive, fast, and simple for chair-side diagnosis of dry mouth. Autoimmune diseases can be accompanied by salivary gland dysfunction. This may be due to the effect of cytokines in the autoimmune process or because of thyroid hormone dysfunctions.