This "shortness of breath" is unlikely to be due to cancer. Even though in later stages of cancer shortness of breath can occur, it very less likely for a cancer to present in this way. This is most likely to be a respiratory cause (as in asthma), anxiety , anemia or a cardiac problem. He/She will need evaluation in form of complete physical examination, +/- Chest xray and other tests depending upon the physical examination findings.
Now if some tests have brought out anemia, it could be very well due to anemia. In night there are many factors operating (like high sympathetic drive, pushed up diaphragm etc) which can actually precipitate an anemia related breathlessness (thus appearing as sudden). The cause of anemia needs to be found out. Anemia can be the presenting symptom of cancer in rare cases.
Hope this helps
Patient replied :
Apart from this unusual shortness of breath, sometime my friend have chest pain also. So I was just wondering that this is not any symptom of any cancerous growth.
And is "Shortness of Breath" 100% curable and what should be included in proper diet.
This is more likely to be non cancerous. 100 percent confirmation can be done (and cancer to be ruled out) can only be done after further tests. Also only if a diagnosis is made as to know what causes the cancer, then only we can say whether it is curable or not. Also about the diet.