Cancer of Unknown Primary (CUP) | I D Cancer Center Lucknow
Expert Diagnosis & Personalised Treatment at I D Cancer Center, Lucknow
Cancer of Unknown Primary (CUP) refers to a group of cancers in which malignant cells are found in the body, but the original site (primary tumour) cannot be identified despite detailed evaluation. CUP accounts for nearly 3–5% of all cancer diagnoses and often requires advanced investigations and a multidisciplinary approach for accurate management.
What is Cancer of Unknown Primary?
CUP occurs when cancer cells have already spread to other parts of the body (metastatic cancer), but the site from where the cancer started cannot be found. This happens because:
The primary tumour is very small
The body's immune system may have destroyed the primary site
The cancer may grow faster at metastatic sites
The tumour location is difficult to detect with standard imaging
CUP occurs when cancer cells have already spread to other parts of the body (metastatic cancer), but the site from where the cancer started cannot be found. This happens because:
The primary tumour is very small
The body's immune system may have destroyed the primary site
The cancer may grow faster at metastatic sites
The tumour location is difficult to detect with standard imaging
Common Symptoms of CUP
Symptoms vary depending on where the metastatic cancer is found. Common signs include:
Unexplained weight loss
Persistent fatigue
Pain in bones, abdomen, or chest
Enlarged lymph nodes
Loss of appetite
Persistent cough or breathing difficulty
Abnormal bleeding
Recurrent fever or general ill-health
Symptoms vary depending on where the metastatic cancer is found. Common signs include:
Unexplained weight loss
Persistent fatigue
Pain in bones, abdomen, or chest
Enlarged lymph nodes
Loss of appetite
Persistent cough or breathing difficulty
Abnormal bleeding
Recurrent fever or general ill-health
How Is Cancer of Unknown Primary Diagnosed?
Accurate diagnosis requires a combination of advanced imaging, pathology, and molecular testing. At I D Cancer Center, we follow a systematic evaluation approach:
Accurate diagnosis requires a combination of advanced imaging, pathology, and molecular testing. At I D Cancer Center, we follow a systematic evaluation approach:
1. Detailed Clinical Examination
Complete medical history
Physical examination including lymph nodes and organ systems
Complete medical history
Physical examination including lymph nodes and organ systems
2. Radiological Imaging
CT scans (chest, abdomen, pelvis)
PET-CT for whole-body metabolic imaging
MRI based on suspected areas
Ultrasound abdomen / neck
CT scans (chest, abdomen, pelvis)
PET-CT for whole-body metabolic imaging
MRI based on suspected areas
Ultrasound abdomen / neck
3. Biopsy & Pathology
Core needle / excisional biopsy
Immunohistochemistry (IHC) panels
Tumour markers
Cytology studies
Core needle / excisional biopsy
Immunohistochemistry (IHC) panels
Tumour markers
Cytology studies
4. Advanced Molecular Tests
Next-generation sequencing (NGS)
Genetic profiling
Biomarker-based origin prediction
These help identify patterns that suggest the most likely primary site and guide personalised treatment.
Next-generation sequencing (NGS)
Genetic profiling
Biomarker-based origin prediction
These help identify patterns that suggest the most likely primary site and guide personalised treatment.
Types of Cancer of Unknown Primary
CUP may be categorised based on the site where metastases are found:
Lymph node metastasis CUP
Bone-dominant CUP
Liver-dominant CUP
Lung metastasis CUP
Peritoneal carcinomatosis of unknown origin
Squamous cell carcinoma in neck nodes with unknown primary
Adenocarcinoma of unknown primary
Each has distinct behaviour and treatment strategies.
CUP may be categorised based on the site where metastases are found:
Lymph node metastasis CUP
Bone-dominant CUP
Liver-dominant CUP
Lung metastasis CUP
Peritoneal carcinomatosis of unknown origin
Squamous cell carcinoma in neck nodes with unknown primary
Adenocarcinoma of unknown primary
Each has distinct behaviour and treatment strategies.
Treatment Options at I D Cancer Center
Our treatment is individualised, based on tumour type, spread, patient health, and likely origin.
Our treatment is individualised, based on tumour type, spread, patient health, and likely origin.
1. Systemic Therapy
Chemotherapy
Targeted therapy (based on gene profile)
Immunotherapy (PD-L1, MSI-high, TMB-high cases)
Chemotherapy
Targeted therapy (based on gene profile)
Immunotherapy (PD-L1, MSI-high, TMB-high cases)
2. Radiation Therapy
Delivered using modern techniques available at I D Cancer Center:
IMRT / VMAT
IGRT-based precision radiotherapy
Stereotactic Radiosurgery (SRS) / SBRT
Bone/pain palliation
Lymph node-directed radiotherapy
Radiation is particularly effective when CUP presents with isolated lymph node or bone involvement.
Delivered using modern techniques available at I D Cancer Center:
IMRT / VMAT
IGRT-based precision radiotherapy
Stereotactic Radiosurgery (SRS) / SBRT
Bone/pain palliation
Lymph node-directed radiotherapy
Radiation is particularly effective when CUP presents with isolated lymph node or bone involvement.
3. Surgery (Selected Cases)
Lymph node excision
Biopsy for diagnostic confirmation
Debulking when necessary
Lymph node excision
Biopsy for diagnostic confirmation
Debulking when necessary
4. Supportive & Palliative Care
Pain management
Nutrition support
Psychological counselling
Symptom-directed care
Pain management
Nutrition support
Psychological counselling
Symptom-directed care
Recent Advancements
CUP treatment has significantly improved with modern tools:
Molecular profiling to predict tissue of origin
Artificial intelligence–based pattern recognition in imaging
Advanced IHC markers
Precision radiation techniques (IMRT/VMAT/SBRT)
Immunotherapy for responsive subtypes
Liquid biopsy to detect tumour DNA in blood
These advancements offer better accuracy and improved survival.
CUP treatment has significantly improved with modern tools:
Molecular profiling to predict tissue of origin
Artificial intelligence–based pattern recognition in imaging
Advanced IHC markers
Precision radiation techniques (IMRT/VMAT/SBRT)
Immunotherapy for responsive subtypes
Liquid biopsy to detect tumour DNA in blood
These advancements offer better accuracy and improved survival.
Prognosis
Prognosis depends on:
Type of metastatic cells (adenocarcinoma, squamous, neuroendocrine)
Extent of disease
Patient’s general health
Response to therapy
With personalised treatment, many CUP patients experience meaningful long-term control and good quality of life.
Prognosis depends on:
Type of metastatic cells (adenocarcinoma, squamous, neuroendocrine)
Extent of disease
Patient’s general health
Response to therapy
With personalised treatment, many CUP patients experience meaningful long-term control and good quality of life.
