G.R. No. 137916 - Development Bank of the Philippines vs. Court of Appeals

Leticia Ador Mora, employed as a telegraph operator of the Bureau of Telecommunications in Tacloban City from 1963 until December 25, 1979.
During her employment, particularly in January 1978, she experienced frequent epigastric pain radiating to the periumbilical region.
A biopsy performed at St. Paul’s Hospital in Tacloban City resulted in a diagnosis of adenocarcinoma of the ileocaecal junction.

Leticia underwent an “exploratory laparotomy with resection of the ileocaecal junction,” yet her medical condition persisted with recurring episodes of illness.
Ultimately, on November 22, 1980, Leticia Mora passed away due to complications from her illness.

Prior to her death, Leticia filed a claim for disability benefits under Presidential Decree No. 626 (as amended) with the Government Service Insurance System (GSIS).
The GSIS denied her claim on the ground that her illness was not considered an occupational disease in view of her job as a telegraph operator.
Dissatisfied with the GSIS decision, a letter was sent to the Chairman of the Employees’ Compensation Commission (ECC), Minister Blas F. Ople, requesting a review of her case.
Following her death, her husband pursued the appeal before the ECC, which ultimately denied her claim for compensation benefits by maintaining that her illness was not work-connected.

The applicable law is the New Labor Code, PD 442 (as amended), effective for injuries, sickness, disability, or death occurring on or after January 1, 1975.
Under Article 167(1) of the New Labor Code (amended by PD 1368), “sickness” is defined to include illnesses definitely accepted as occupational diseases or any illness caused by employment when proof shows that the risk of contracting it is increased by the working conditions.
The ECC, in its amended Rules, Section 1(b), Rule III, outlined that for an illness to be compensable, it must either be listed in Annex “A” as an occupational disease or be proven that the work conditions increased the risk of contracting the illness.
In Leticia Mora’s case, her ailment (adenocarcinoma of the ileocaecal junction) was not listed in Annex “A” and the cause of the disease—cancer—remains undetermined even by medical science.

Medical experts acknowledged that while carcinoma of the small intestine, particularly adenocarcinoma, has known clinical manifestations (including intestinal obstruction and abdominal pain), its cause cannot be determined with absolute certainty.
Citing previous decisions (e.g., Mercado, Jr. v. ECC and Flaviano Nemaria v. ECC/GSIS), it was emphasized that the requirement to prove a causal link between the disease and employment applies only when the cause is known. If unknown, such proof is not demanded, under penalty of creating an impossible condition for the claimant.

The ECC, as well as the GSIS, had maintained that Leticia Mora’s illness was not work-related, thereby denying the claim for compensation benefits.
The petition for review on certiorari sought to set aside and annul the ECC’s decision, arguing that due to the impossibility of proving the cause of cancer, the strict requirement should be liberalized in light of the encompassing social justice goals of the employee’s compensation system.

Whether the adenocarcinoma of the ileocaecal junction, which was not specifically classified as an occupational disease in Annex “A” of the ECC Rules, can be considered work-connected merely by inferring that her prolonged employment might have increased the risk of contracting the illness.

Whether imposing the burden of demonstrating that the working conditions directly caused or increased the risk of Leticia Mora’s ailment is appropriate when the causation of the disease is medically undetermined.
Whether the law’s liberal provisions under the New Labor Code justify awarding compensation without satisfying the impossible condition of proving the precise cause of cancer.

Whether the ECC and GSIS acted within their discretion or whether the principles of social justice and the liberal interpretation of compensability under the New Labor Code require a more favorable decision in favor of the claimant.