Cancer　continues　to　be　the　most　dangerous　disease　around　the　world;　it　causes　electrolyte　imbalance　as　well　as　metabolic　changes.　There　is　a　complicated　relationship　between　electrolyte　disorder　and　cancer.　Cancer　patients　commonly　pass　with　abnormalities　in　serum　electrolyte　levels　such　as　hypokalemia,　hyperkalemia,　hyponatremia,　and　hypercalcemia.　So,　these　electrolyte　imbalances　indicate　the　existence　of　paraneoplastic　processes　and　help　come　to　a　more　informed　prognosis.　Hypokalemia　is　defined　as　a　serum　potassium　concentration　below　3.5　mmol/L　and　it　is　the　second　common　electrolyte　imbalance　seen　in　patients　with　malignant　diseases.　In　this　paper,　the　contribution　of　serum　potassium　concentration　to　tumor　progression　was　studied　by　applying　a　promising　and　non-invasive　technique　called　laser-induced　breakdown　spectroscopy　(LIBS).　It　was　found　that　there　is　a　correlation　between　hypokalemia　and　the　colorectal　cancer　problem.　Also,　significant　serum　potassium　concentration　differences　were　detected　among　two　different　stages　of　the　same　cancer　and　also　between　two　groups　of　the　same　stage　of　a　cancer　held　in　common　but　one　of　them　suffers　from　hypercalcemia.　In　addition,　the　optimum　conditions　of　LIBS　setup　were　arranged　such　that　it　will　be　suitable　to　work　with　serum　samples　on　glass　substrate.