An 80-year-old female who has never taken estrogen, develops pink vaginal discharge. An endometrial biopsy shows an adenocarcinoma of the endometrium. Papanicolaou smear is negative. Of the following what is the most important indicator of prognosis?
Prognostic factors in endometrial adenocarcinoma

Most important prognostic factor is lymph node metastasis
Age at diagnosis (older the patient poorer the prognosis).
Stage of the disease.
Histologic type (endometriod adenocarcinoma have good prognosis, clear cell carcinoma have poor prognosis).
Histologic grade .
Myometrial penetration (Increasing depth of invasion is associated with increasing likelihood of extrauterine spread and recurrence).
Extension to cervices, Involvement of cervix, isthmus or both is associated with increased risk of extrauterine disease and LN metastasis.
Tumor size (> 2 cm-more lymph node metastasis).
Hormone receptor status (receptor positive-better prognosis).
Ploidy status: Aneuploid have got better prognosis compared to diploid tumors.
Oncogene expression: HER: 2/neu, k-ras poor prognosis.
Role of Peritoneal cytology on prognosis is controversial.
Body habitus
Level of CA-125
Nutritional status
Histologic type of tumour