Hi Ravikumar,

Welcome to Grace.  Cancer can't be identified by its symptoms which is just one of its insidious ways.  Early and many later symptoms look like other less dire and common illnesses  Night sweets and losing weight without trying are typical of all cancers.  Swollen lymph nodes and fatigue are seen in blood cancers in particular.  Biopsy is the only way to know that symptoms are from cancer. 

From the Mayo Clinic, "Leukemia symptoms vary, depending on the type of leukemia. Common leukemia signs and symptoms include:

• Fever or chills
• Persistent fatigue, weakness
• Frequent or severe infections
• Losing weight without trying
• Swollen lymph nodes, enlarged liver or spleen
• Easy bleeding or bruising
• Recurrent nosebleeds
• Tiny red spots in your skin (petechiae)
• Excessive sweating, especially at night
• Bone pain or tenderness"

Also from the Mayo Clinic, "Signs and symptoms of lymphoma may include:

• Painless swelling of lymph nodes in your neck, armpits or groin
• Persistent fatigue
• Fever
• Night sweats
• Shortness of breath
• Unexplained weight loss"

I hope this helps.

All the best,

Janine