Hypocalcemia in cancer

Superscan Pattern on Bone Scintigraphy: A Comprehensive Review

BACKGROUND/OBJECTIVES

The superscan pattern is a characteristic finding on bone scintigraphy, associated with a variety of metabolic bone diseases, malignancies, and other conditions. This pattern is characterized by a diffuse and intense uptake of radiotracer throughout the entire skeleton. Despite being a relatively rare finding, the superscan pattern can have significant clinical implications.

METHODS

This comprehensive review summarizes the available literature on the superscan pattern, focusing on its pathophysiology, clinical significance, and differential diagnoses. Relevant studies and case reports were analyzed to outline the diagnostic challenges associated with the interpretation of bone scintigraphy featuring the superscan pattern.

RESULTS

The literature highlights the clinical significance of the superscan pattern in various metabolic and oncologic conditions. Misinterpretation of this pattern can lead to diagnostic challenges, especially in distinguishing it from other pathologic conditions. Differential diagnosis remains crucial in the accurate interpretation and subsequent management of patients with this finding.

CONCLUSIONS

This review provides a comprehensive overview of the superscan pattern on bone scintigraphy, aiming to assist clinicians in recognizing and managing this rare yet clinically important finding.

Hypocalcemia: a key biomarker in hospitalized COVID-19 patients

Background

At the end of 2019 a new respiratory syndrome emerged in China named Coronavirus disease 2019 (COVID-19) due to SARS-CoV-2 infection. Considering the severity of the disease in adult subjects with one or more chronic pathologies, it was mandatory to find simple and effective biomarkers for negative prognosis of the disease easily available at the admission to the hospital.

Methods

To identify possible parameters showing association with the outcome in COVID-19 patients with pre-existing chronic diseases, blood biochemical profiles of 511 patients, enrolled from March to June 2020, were retrospectively evaluated. The pathological conditions taken into consideration were diabetes, arterial hypertension, chronic kidney disease, cardiovascular diseases, chronic obstructive pulmonary disease, obesity, and cancer. All the data were collected upon admission to the emergency room (ER) during the indicated period.

Results

We observed that serum and ionized calcium were prevalently altered in our cohort. We determined that hypocalcemia was a major parameter associated with mechanical ventilation and poor prognosis, correlating also with the presence of comorbidities such as cardiovascular diseases, chronic kidney disease, and cancer. In addition, we found a positive correlation between hypocalcemia and clinical complications during hospitalizations.

Conclusions

Our results strengthen the relevance of serum calcium concentration as a useful prognostic biomarker in hospitalized COVID-19 patients.

Denosumab in patients with cancer and skeletal metastases: a systematic review and meta-analysis

BACKGROUND

We conducted a systematic review of the literature to determine the efficacy and safety of denosumab in reducing skeletal-related events (SRE) in patients with bone metastases.

METHODS

A literature search using MEDLINE, EMBASE, Web of Science and The Cochrane Collaboration Library identified relevant controlled clinical trials up-to-March 14, 2012. Two independent reviewers assessed studies for inclusion, according to predetermined criteria, and extracted relevant data. The primary outcomes of interest were SRE, time to first on-study SRE, and overall survival. Secondary outcomes included pain, quality of life, bone turnover markers (BTM), and adverse events.

RESULTS

Six controlled trials including 6142 patients were analyzed. Compared to zoledronic acid, denosumab had lower incidence of SRE with a risk ratio (RR) of 0.84 (95% confidence intervals (CI) 0.80-0.88), delayed the onset of first on-study SRE (RR 0.83; 95% CI 0.75-0.90) and time to worsening of pain (RR 0.84; 95% CI 0.77-0.91). No difference was observed in overall survival with pooled hazard ratio of 0.98 (95% CI 0.90-1.0). For total adverse events, denosumab was similar to zoledronic acid (RR 0.97; 95% CI 0.89-1.0). No significant differences were observed in the frequency of osteonecrosis of the jaw (RR 1.4; 95% CI 0.92-2.1). Patients on denosumab had a greater risk of developing hypocalcemia (RR 1.9; 95% CI 1.6-2.3).

CONCLUSIONS

Denosumab was more effective than zoledronic acid in reducing the incidence of SRE, and delayed the time to SRE. No differences were found between denosumab and zoledronic acid in reducing overall mortality, or in the frequency of overall adverse events.

Hypocalcemia associated with bone metastases in a patient with salivary-gland carcinoma

BACKGROUND

A 70-year-old man presented with a smooth lump on his buccal mucosa and right-sided cervical lymphadenopathy. Staging investigations revealed extensive sclerotic bone metastases and the patient subsequently underwent palliative radiotherapy to the right face and cervical region. Seven months later he presented with a 4-day history of fatigue, muscle cramps, ataxia, paraesthesia, and blurred vision.

INVESTIGATIONS

Physical examination, biopsy of abnormal buccal mucosa, routine biochemistry, electrocardiogram, bone scan, CT scans of the chest, abdomen and pelvis, and MRI of the brain.

DIAGNOSIS

Undifferentiated carcinoma of the salivary gland with sclerotic bone metastases and hypocalcemia.

MANAGEMENT

Palliative radiotherapy to the right face and cervical region, infusions of calcium gluconate and calcium chloride, oral calcium carbonate, vitamin D and magnesium, palliative chemotherapy (carboplatin and 5-fluorouracil), and whole brain radiotherapy.

Chemotherapy decreases epiphyseal strength and increases bone fracture risk

To establish the effect of three frequently used chemotherapeutic agents in childhood cancer on the skeleton, growing male Wistar rats were studied. Treatment with doxorubicin, methotrexate, and cisplatin reduces the proximal tibial growth plate shear strength because of a decreased surface area and maximum shear stress. After treatment the bone fracture risk of the tibia and femur is increased because of decreased bending resistance. Doxorubicin and cisplatin reduce the maximum shear stress of the proximal tibial growth plate, none of the chemotherapeutic agents inhibit bone mineralization. These effects are caused by treatment-induced malnutrition and the accompanying weight reduction and a direct effect of the chemotherapeutic agents on the skeleton. The current study confirmed the importance of preventing malnutrition during chemotherapeutic treatment in view of possible skeletal complications. During followup of children treated with chemotherapy, attention should be given to signs and symptoms suggestive of such complications.

The effect of chemotherapy on the morphology of the growth plate and metaphysis of the growing skeleton

AIM

To establish the effect of three single chemotherapeutic agents on the growing skeleton, male Wistar rats were studied.

METHODS

From the age of 4 weeks the rats were given iv doxorubicin (DOX) 15 mg/m(2) body surface area (BSA), methotrexate (MTX) 60 mg/m(2) BSA or cisplatin (CDDP) 7.5 mg/m(2) BSA. One non-treated control group was fed ad libitum (ad lib) and for every drug-treated group there was a diet-control group. After dissection at 13 weeks of age, morphology of the proximal tibial growth plate and metaphysis were studied.

RESULTS

Compared to the ad lib group, DOX significantly decreased and MTX increased growth plate height (P<0.05). CDDP decreased height of the proliferating layer (P<0.05). Trabecular volume was decreased in the DOX and CDDP treated rats compared to the ad lib group (P=0.054). Compared to the diet control group trabecular bone volume was unaffected in the DOX group and decreased in the MTX and CDDP group (P<0.05).

CONCLUSIONS

Doxorubicin causes growth plate thinning, methotrexate increases growth plate height and cisplatin does not affect growth plate height. All three chemotherapeutic agents decrease the trabecular volume of the proximal tibial metaphysis. Part of the effect of DOX, MTX and CDDP is related to the treatment induced malnutrition.

The effect of chemotherapy on the growing skeleton

With the increasing use of high dose (poly)chemotherapy schedules in the treatment of childhood cancer it is particularly important to know the adverse effects of these treatments. Growth is a complex mechanism affected not only by chemotherapy but also by the malignancy itself as well as nutritional status, the use of corticosteroids and (cranial) radiation. In vitro and animal studies are often the most useful in determining the effect of a single chemotherapeutic agent on the growing skeleton. In vitro studies have shown doxorubicin, actinomycin D and cisplatin to have a direct effect on growth plate chondrocytes that in animals results in decreased growth and final height. Clinical studies with multiagent chemotherapy have demonstrated that antimetabolites decrease bone growth and final height. Childhood cancer survivors are at risk of a reduced bone mineral density, mainly due to methotrexate, ifosfamide and corticosteroids. This reduced bone mineral density persists into adult life and may increase bone fracture risk at an older age.

Severe hyperphosphatemia following acute tumor lysis syndrome

We report on a 14-year-old boy with acute lymphoblastic leukemia (lymphoma-leukemia) who had two episodes of acute tumor lysis syndrome during induction of remission with oral prednisolone alone and oral prednisolone, intravenous vincristine, and doxorubicin, respectively. Subsequently he had severe hyperphosphatemia (29.3 and 14.1 mg/dl; 9.46 and 4.55 mmol/L), hypocalcemia, hyperuricemia, hyperkalemia, and azotemia. Multiple stones and tumor cells infiltration were demonstrated in both kidney. He responded favorably to hemodialysis.

Case report: clinical hypocalcemia: the endocrine conference of the Alton Ochsner Medical Institutions and Tulane University Medical Center

The authors present the case of an 81-year-old woman with severe hypocalcemia due to osteoblastic metastases from breast cancer. The clinical and laboratory characteristics of this condition are discussed, some therapeutic dilemmas considered, and the literature briefly reviewed.

Acute tumour lysis syndrome with no evidence of tumour load

Acute tumour lysis syndrome (ATLS) is a well-recognised complication of the treatment of a variety of malignant disorders in which a large mass of disease is obvious. ATLS may, however, occur even in the absence of bulk disease. We present two cases which, together with a review of previously reported cases, suggest that a cause of this rare phenomenon is primary renal lymphoma which subsequently develops into the leukaemic phase. This is supported by the observation that some bone marrow aspirates which are normal at the time of ATLS have shortly afterwards demonstrated lymphoblasts. Renal biopsy may not exclude primary lymphoma of the kidney. In excluding lymphoproliferative disease in the differential diagnosis of acute hyperuricaemia, the importance not only of bone marrow examination but of exhaustive investigation of the kidneys is stressed.

Hypocalcemic emergencies

The approach to the hypocalcemic patient is best considered with due regard to the underlying etiology and the extent to which features of hypocalcemia are present. When hypocalcemia is a medical emergency, aggressive but judicious measures must be taken immediately to correct, in part, the hypocalcemia. Parenteral therapy of hypocalcemia is advisable only under these conditions. The aim of acute management is not to return the serum calcium to normal but rather to ameliorate the acute manifestations of hypocalcemia. If the hypocalcemic state is owing to a chronic condition that will not remit, a plan for long-term management with a vitamin D preparation and calcium supplementation is implemented after the emergency therapy is provided.

Management of disorders of calcium homoeostasis

Severe hypercalcaemia may be life-threatening and requires prompt management. Whatever the cause, the aim of therapy should obviously be to eradicate the source of hypercalcaemic factors. After rehydration, which is an essential first step in the management strategy, and after evaluation of the prevailing pathogenetic mechanism, the acute treatment will be aimed at increasing urinary Ca excretion and inhibiting bone resorption. Among the various pharmacological agents, bisphosphonates appear to be the drugs of first choice, because of their efficacy and their virtual absence of side-effects. The decision to treat hypocalcaemia is determined by the extent of the symptoms and the risk of complications. The treatment of acute hypocalcaemia comprises the parenteral administration of Ca or magnesium, when magnesium deficiency can be suspected. Then, chronic hypocalcaemia may require the use of 1,25-dihydroxyvitamin D, once the replenishments of vitamin D stores have been assured.