What are the different types of cancer and their treatments?

Types of Cancer and Their Treatments

Cancer is characterized by the proliferation of cells that have evaded central endogenous control mechanisms, with different types classified according to their tissue of origin and increasingly by their molecular characteristics. 1

Major Types of Cancer

Carcinomas

• Carcinomas arise from epithelial cells that line organs or tissues and are the most common type of cancer 2
• Begin as clonal proliferation of cells with acquired mutations that progress to invasive carcinoma when cells breach the underlying basement membrane 2
• Common subtypes include:
  • Adenocarcinoma (well and moderately differentiated) 3
  • Squamous cell carcinoma 3
  • Poorly differentiated carcinoma 3

Hematologic Malignancies

• Acute Lymphoblastic Leukemia (ALL)
  • Treated with BFM regimen, a cornerstone multiagent chemotherapy protocol 4
  • Treatment includes a 4-drug induction with vincristine, anthracycline, corticosteroid, and L-asparaginase 4
  • Risk stratification based on factors like WBC count, hypodiploidy, and MLL/KMT2A rearrangements 4

Bone Cancers

• Osteosarcoma
  • First-line therapy includes cisplatin and doxorubicin or MAP (high-dose methotrexate, cisplatin, and doxorubicin) 3
  • Second-line therapy options include docetaxel and gemcitabine, cyclophosphamide and etoposide, or ifosfamide and etoposide 3
• Ewing's Sarcoma
  • First-line therapy includes VAC/IE (vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide) 3
  • Second-line therapy includes cyclophosphamide and topotecan or temozolomide and irinotecan 3
• Chondrosarcoma
  • Conventional chondrosarcoma has no known standard chemotherapy options 3
  • Mesenchymal chondrosarcoma follows Ewing's regimens 3
  • Dedifferentiated chondrosarcoma follows osteosarcoma regimens 3

Breast Cancer

• Classified into stages:
  • Noninvasive carcinomas (LCIS and DCIS; stage 0) 3
  • Operable local-regional invasive carcinoma (stages I, II, and some IIIA) 3
  • Inoperable locoregional invasive carcinoma (stages IIIB, IIIC, and some IIIA) 3
  • Metastatic disease (stage IV) 3
• Treatment depends on hormone receptor status, HER2 status, and stage 3
• Tamoxifen is used for hormone receptor-positive breast cancer, reducing the incidence of invasive breast cancer by 43% in DCIS 5

Lung Cancer

• Divided into two major classes: Non-Small Cell Lung Cancer (NSCLC) and Small Cell Lung Cancer (SCLC) 3
• NSCLC accounts for more than 85% of all lung cancer cases 3
• Major types of NSCLC include:
  • Nonsquamous carcinoma (adenocarcinoma, large-cell carcinoma) 3
  • Squamous cell (epidermoid) carcinoma 3
• Screening high-risk patients with low-dose helical CT decreases mortality by 20% compared with chest radiograph 3

Cancer of Unknown Primary (CUP)

• Represents 3-5% of all malignancies 3
• Categorized into:
  • Well and moderately differentiated adenocarcinomas 3
  • Poorly differentiated carcinomas 3
  • Squamous cell carcinomas 3
  • Undifferentiated neoplasms 3
  • Carcinomas with neuroendocrine differentiation 3

Treatment Approaches

Surgery

• For bone cancer, wide excision should achieve histologically negative surgical margins 3
• Limb-sparing resection is preferred to optimize function if reasonable functional expectations can be achieved 3
• Multidisciplinary team evaluation is essential for primary bone tumors and selected metastatic tumors 3

Radiation Therapy

• Approximately 50% of all cancer patients receive radiation therapy during their course of illness 6
• Contributes towards 40% of curative treatment for cancer 6
• Main goal is to deprive cancer cells of their multiplication potential 6
• Specialized techniques include intensity-modulated radiation therapy, particle-beam RT, stereotactic radiosurgery, or fractionated stereotactic radiotherapy 3

Chemotherapy

• Regimens are specific to cancer type and stage 3
• For bone cancer, fertility issues should be addressed with patients prior to commencing chemotherapy 3
• Drug resistance is a significant challenge in cancer treatment, occurring through various mechanisms including tumor microenvironment factors, genetic mutations, changes in surface drug receptors, and increased drug efflux 7

Targeted Therapy

• Based on molecular characteristics of cancer cells 1
• Allows for more precise and potentially less toxic cancer therapies 1
• Tamoxifen is an example of targeted therapy for hormone receptor-positive breast cancer 5

Multidisciplinary Approach

• Cancer care should be delivered by a multidisciplinary team with expertise in managing specific tumor types 3
• The team should meet regularly and include specialists from various disciplines 3
• For CUP, treatment depends on the subtype:
  • Poorly differentiated carcinoma with nodal disease: platinum-based combination chemotherapy 3
  • Peritoneal carcinomatosis in females: similar to FIGO III ovarian cancer 3
  • Isolated axillary nodal metastases in females: treated like breast cancer 3
  • Squamous carcinoma of cervical lymph nodes: radiation for N1-N2 disease, induction chemotherapy for higher stages 3

Future Directions

• Rapid technological advances now allow detailed molecular analysis of different cancer types 1
• Accumulating knowledge about cancer development and progression is being used to develop more precise diagnostics and more effective treatments 1
• The goal is to offer each cancer patient a therapeutic regimen tailored to their individual disease and situation 1
• Research continues to accelerate the development of new and more effective treatments for cancer 8