Rare chest cancers

Lung cancer

Lung cancer is extremely rare in children and adolescents, only accounting for about 0.2% of all childhood cancers. In children, the ratio between the inflammation, lung metastases and primary lung cancer is 60 : 5 : 1.

Pleuropulmonary blastoma (PPB)

Pleuropulmonary blastoma (PPB) is an intrathoracic mesenchymal tumour which typically arises from peripheral parts of lung in children under the age of 6. According to the International Pleuropulmonary Blastoma Registry, up to 40% of PPBs develop as a result of a genetic predisposition and a mutation of the DICER-1 gene. Clinical symptoms are usually present when the tumour mass is large enough to cause health problems: dry cough, dyspnoea and tachypnoea, respiratory insufficiency, and the relocation of midline structures to the healthy side. Histological examination is needed to establish the diagnosis.

According to the Dehner’s classification, there are three types of PPB:

  1. cystic
  2. cystic-solid
  3. solid

Radical surgical resection is the choice of treatment, followed by chemotherapy and radiotherapy. The prognosis depends on the radicality of surgery, absence of invasiveness, spreading to neighbouring organs (pleura, thoracic wall, lymph nodes), and the type of PPB. As for PPB type I, five-year survival rates range between 85 to 91 percent. Five-year survival is much worse in type II and type III, averaging 50 %.

Lung carcinoma

Primary lung adenocarcinoma is extremely rare in children; the median age at the time of diagnosis is about 15 years. Most cases are the so-called spontaneous carcinomas (developing in non-smokers) with an aggressive behaviour, fast local progression, and an early dissemination. In up to 75% of patients, the disease is diagnosed at an advanced stage, which is due to two reasons: firstly, this type of cancer is not expected to develop in a young person; and secondly, there are no early warning signs of lung cancer. All clinical symptoms (both pulmonary and extrapulmonary) are signs of an advanced disease. It is necessary to think about the possibility of lung cancer if pathological changes on the chest x-ray persist despite an adequate treatment. There are no studies on paediatric patients treated for lung cancer; treatment is based on recommendations for adults (surgery, chemotherapy, biological therapy). The prognosis is extremely poor: the average survival time does not exceed 8–12 months.

Bronchial cancer

Bronchial cancer in paediatric patients is represented by two tumour types: a well-differentiated neuroendocrine tumour (carcinoid), and a mucoepidermoid carcinoma. Both tumour types are localised in either main or lobar bronchi. The most common clinical symptoms involve signs of obstruction and a recurrent localised pneumonia. The disease is often misdiagnosed and mistreated as asthma. Both tumour types are classified as cancers with a low degree of malignancy, and have an excellent prognosis after a radical resection (lobectomy or unilateral pneumonectomy is often necessary).

Heart cancer

Benign tumours (rhabdomyoma, fibroma, myxoma, teratoma) are much more common than primarily malignant tumours – sarcomas (only about 10%). More frequently, heart is affected by a metastatic process during the generalisation of another malignant tumour (rhabdomyosarcoma, Ewing’s sarcoma, leukaemic infiltration, or lymphoma). Causes of origin are usually unknown; cardiac rhabdomyosarcoma is the first manifestation of tuberous sclerosis. Most benign cardiac tumours are diagnosed prenatally (from the 20th week of pregnancy onwards) or in early infant age (before one year of age). Myxomas are more common in adolescents. Clinical symptoms are unspecific, depending mainly on the location and size of the tumour (arrhythmia, obstruction of blood flow, syncope, or even sudden death in extreme cases). Treatment depends on tumour type, location, size, and clinical symptoms. Surgical treatment is indicated only in symptomatic tumours. The role of heart transplantation in primarily malignant heart tumours in children is not clear, nor unequivocally defined. Prognosis is usually very good for benign tumours: rhabdomyomas often regress spontaneously over time. For malignant heart tumours, however, the prognosis is very poor: the average survival time ranges from 6 to 10 months.

Breast cancer

Breast tumours in children and adolescents are usually benign (juvenile fibroadenomas) or of borderline malignancy (phylloides tumours). Only about 0.2% of malignant breast tumours are diagnosed in girls under the age of 20. Among carcinomas, the most common diagnosis is the invasive ductal carcinoma with lymphovascular invasion, which is usually hormone-receptor-negative, and has a worse prognosis than the same type of cancer in older women (detection in an advanced stage, late diagnosis, less favourable biological characteristics). Adolescent girls with a hereditary predisposition (mutations in the BRCA1 and/or BRCA2 gene) are at a higher risk of developing breast cancer. A palpable lump in the breast is usually reported as a clinical symptom of benign and malignant breast tumours.

As for benign tumours, surgery is indicated only in case of clinical problems, tumour growth, or an atypical ultrasound image. In phylloides tumours, radical resection is the choice of treatment. Treatment of carcinomas is complex, according to recommendations valid for adult breast cancer patients. In general, young age is a significantly negative prognostic factor for breast cancer patients.